







Prisms 
20170901 

From Christa: What do all prisms have in common? Answered by Penny Nom. 





Sloping my yard away from my house 
20160415 

From Harold: I need to slope a area of my yard away from my house and garage. The length of my house is 80 feet long and i need to slope it 22 feet away. I want to raise the dirt at the foundation by 6 inches and slope it down to nothing at the width of 22 feet. How much soil would i require? Answered by Penny Nom. 





The volume of a box with a hexagonal base 
20160327 

From Frank: how many gallons of water in an 8" hexagon shaped box. 6" sides x 12.5" high ? The walls are 1" thick , beveled @ 30 degrees, so inside dimensions are 6" Answered by Penny Nom. 





A rectangular prism 
20160302 

From Paula: Trying to help with a math problem. I don't know how to set up the equation for this.
A rectangular prism has a volume of 7.875m3rd and a height of 3.5 m. What is the area of the base of the prism?
Thanks for your help! Answered by Penny Nom. 





The surface area of a triangular prism 
20150603 

From Alex: Find the surface area of a triangular prism with Isoceles triangles and dimensions 4 feet by 6 feet Answered by Penny Nom. 





The volume of a trench 
20150311 

From Kim: A trench 60m long and 15m deep, 12m wide at the top and 8m wide at the bottom.How many cubic meters of earth have been removed? Answered by Penny Nom. 





A tennis ball in a triangular prism 
20141006 

From Anna: Hi, I need to find the the base and the height of a triangular prism, but I only know the diameter of a tennis ball that fits exactly in the triangular container.. The diameter for the ball is 8.50cm.
Can you help me find the formula?
Thank you! Answered by Penny Nom. 





A barge of triangular cross section 
20140818 

From tushar: a barge of triangular cross section is 20m long 12 m wide and 6m deep.its floats in SW at a draft if 4m find its displacement Answered by Penny Nom. 





The volume of hexagonal pyramid and hexagonal prism 
20140518 

From visshwam: how to find volume of hexagonal pyramid and hexagonal prism?
my measurements are each side of pyramid's triangle is 1"x2"x2".
hexagon prism is 2"x1" each side Answered by Penny Nom. 





Two rectangular prisms 
20140410 

From hannah: two rectangular prisms have a combined volume of 432 cubic feet Prism A has half the volume prism b has what are the volumes of prism a and prism Answered by Penny Nom. 





The surface area of a rectangular prism 
20140408 

From Manraj: Find the surface area of a rectangular prism with dimensions 4, 5, and 7 units. Answered by Penny Nom. 





Can a cylinder be considered a circular prism? 
20140208 

From Davina: Can a cylinder be considered a circular prism? Answered by Penny Nom. 





A railroad embankment 
20130122 

From clint: the pennsylvania railroad found it necessary,owing to land slides upon the roadbed,to reduce the angle of inclination of one bank of certain railway cut near pittsburgh,pa.,from an original angle of 45 degrees to a new angle of 30 degrees. the bank as it originally stood was 200 ft.long and had a slant length of 60 ft.. find the amount of the earth removed, if the top level of the bank remained unchanged. Answered by Penny Nom. 





Cones, pyramids, cylinders and prisms 
20120913 

From Roy: I read on this page that a pyramid is a special kind of cone, but a cone is not a pyramid. Does this apply to cylinders. Is a prism a special kind of cylinder, but a cylinder is not a prism? Answered by Robert Dawson. 





The volume of a wedge 
20120528 

From olwethu: volume of wedge that have side 3,3 cm and 6,2 cm and 20 cm long? Answered by Penny Nom. 





A rectangular prism 
20120405 

From Tori: How do you find the base height if the base width is 10ft. The height is 7ft. And the volume is105ft. Answered by Penny Nom. 





A trapezoidal prism filled with sand 
20120312 

From Maria: could a Trapezoid that is 80 inches high with a 54 inch width top and a 89 inch width bottom and a 80 inch depth hold 58 cubic yards of sand? Answered by Robert Dawson. 





The volume of a dugout 
20120128 

From Jan: is there a formula for calculating the cubic yardage removed from a dugout
for example that is forty feet wide by one hundred and twenty feet long by
twelve feet deep with a three to one slope? It is the slope that makes it a
little tricky. Thank you. Answered by Penny Nom. 





The volume of a hexagonal prism 
20110919 

From Denise: I am being asked to find the volume of a hexagonal prism, base edges are 3cm, and a height of 15cm. The book that I am working from says that the answer is 77.94cm(cubed) but no matter what the equation I use I always get the answer 116.9/117. Please help! Thank you! Answered by Penny Nom. 





The volume of a decagonal prism 
20110529 

From Susan: How do you find the volume of a decagonal prism? Answered by Penny Nom. 





The volume of a triangular shaped aquarium 
20110507 

From Jeff: HI, I searched the site but really couldn't find my answer,
at least that I could understand! I have a triangular shaped aquarium
( think of a cube, except its an equal triangle shape). all 3 sides are 48 inches,
and it is 34" tall. Can you please tell me what the volume is in gallons?
Thanks! Answered by Penny Nom. 





A rectangular prism 
20100427 

From Savannah: A rectangular prism is made of exactly 8 cubes. Find
the length, width, and height. Answered by Penny Nom. 





The base area of rectangular prism 
20100305 

From Desiree: How do you find the base area of rectangular prism that has 4 cm by 4cm by 6cm ? Answered by Penny Nom. 





A prism and a pyramid 
20100219 

From Juanita: What is the relationship between the volume of a prism and a pyramid with congruent base areas and heights? Answered by Tyler Wood. 





A triangular prism 
20100113 

From Breon: what is the formula for a triangular prism? Answered by Robert Dawson. 





Truncated Octagonal Prism 
20091226 

From freitas: the top plane of the truncated octagonal right prism is 45 degree with respect to horizontal. find the volume Answered by Janice Cotcher. 





Draw a net for a rectangular prism? 
20090529 

From Mohamad: Draw a net for a rectangular prism?
Last week when we were studying for our finals we came across a section about drawing nets I would really appreciate it if you gave me some help on it Answered by Robert Dawson. 





The dimensions of a toy chest 
20090507 

From charlotta: My son needs to find the 3 dimensions of a toy chest that has to have a volume of 24 cubic feet can you show how to get the answer Answered by Penny Nom. 





Rectangular prisms 
20090501 

From deborah: Could you please tell me some examples of different objects in the real world of rectangular prisms? Answered by Harley Weston. 





Volume of a prism 
20090421 

From David: The base of a rectangular prism has an area of 15.3 square inches and a volume of 185.13 cubic inches. Write an equation that can be used to find the height "h" of the prism Answered by Robert Dawson and Stephen La Rocque. 





How many rectangles are in a square prism? 
20090409 

From Lorenya: How many rectangles are in a square prism? Answered by Robert Dawson. 





Square prisms and pyramids 
20090403 

From Sheyna: What are the differences between a square prism and a pyramid?
 Sheyna Answered by Penny Nom. 





A rectangular prism 
20090225 

From Christina: I am trying to find the area of the base of a rectangular prism where one cube=_1 cu in. The Answer is given in square inches. I also need the volume of the prism in cu in. For example length=3, w=2, h=5 Answered by Penny Nom. 





The surface area of a cube and rectangular prism 
20090216 

From Mhiko: how to derived the total surface area of a cube and rectangular prism using geoboard?? Answered by Robert Dawson. 





Solid figures 
20090210 

From Rebecca: I need to know the names of solid figures. I have several pictures that I need to answer what type they are.
Thanks, Rebecca 3rd grade Answered by Penny Nom. 





The amount of concrete in a football stand 
20090130 

From jacques: A football stand 150 yd long has 20 tiers of seats; each tier has a rise of 2ft and tread of 3ft.Its construction of reinforced concrete with a cross section as shown. Find the amount of the material used in its construction. Answered by Penny Nom. 





The volume of a prism 
20090119 

From Mady: What is the general equation used to find the volume of a triangular prism? Answered by Robert Dawson and Harley Weston. 





A rectangular prism 
20090113 

From nika: How many bases does a rectangular prism have? What are they? Answered by Harley Weston. 





Triangular prisms and pyramids 
20090110 

From KJ: What are some items found in a home or school that could be considered a triangular prism or triangular pyramid? Answered by Robert Dawson and Penny Nom. 





Volume of a Shed 
20080724 

From lou: I need to know the interior volume in cubic feet of a shed with the dimensions 8' x 10' x 7' with a roof peak of 9'. Thanks Answered by Janice Cotcher. 





A right prism with a square base 
20080613 

From Malik: Question from Malik:
A company wants to alter the dimension of container. The new container is in the shape of right prism equivalent to the current one.
The current container has height of 12cm and square base. The new container has also square base, but in the dimension base is increased by 3cm and height is decreased by 5cm.
if the cardboard is used to manufacture the new container, what area of cardboard is used to make new container? Answered by Penny Nom. 





An octagonal prism 
20080427 

From Melanie: My son is identifying geometric shapes in the real world? We are stuck on octagonal prism, rectangular prism and square prism. Can you help me out with some examples. Thanks Answered by Penny Nom. 





A solid figure with 3 rectangular faces and 2 triangular faces 
20080417 

From Emily: I am in the 3rd grade and my teacher gave us a question. What is a
solid figure with 3 rectangular faces and 2 triangular faces? Answered by Penny Nom. 





A rectangular prism 
20080331 

From Chanlie: i need need to find a rectangular prism with a total surface area of 210 units. Answered by Penny Nom. 





Triangular prisms and pyramids 
20080303 

From LORENA: hi i am in yr 6 and i need to know how many faces,vertices and edges these shapes have..
. TRIANGULAR PYRAMID
. TRIANGULAR PRISM Answered by Penny Nom. 





The volume of a truncated prism 
20080303 

From jhey: The volume of a truncated prism is 6240 cu cm. The base is a right section in the form of an equilateral triangle. The edges perpendicular to the base are 15 cm, 18 cm, and 15 cm long. Find the length of one side of the base. Answered by Harley Weston. 





A rectangular prism 
20071116 

From nicholas: What is the height the surface area to a rectangular prism with a volume of 350 milliliters? Answered by Stephen La Rocque. 





The volume of a regular octagonal prism 
20071020 

From Chris: I am trying to figure out the volume of a regular octagonal prism, with side lengths of 4 inches. How do I do this? Answered by Penny Nom. 





A truncated prism 
20070924 

From Simon: What is the name of a triangular prism with the top of the top of the prism cut off called please.
It is therefore flat on top and flat on the bottom with prism sides. Thanks. Answered by Harley Weston. 





The surface area of a prism 
20070821 

From Iliyas: State the area of prism with logical proof? Answered by Penny Nom. 





Prisms and pyramids 
20070802 

From taryn: two similarities between prism and pyramid Answered by Penny Nom. 





A right rectangular prism 
20070610 

From Wendy: if a right rectangular prism volume is 36cubic cm how can i find the base and height. Answered by Penny Nom. 





The volume of a triangular prism 
20070601 

From Hannah: How do I find the area of the base of a triangular prism, so that I can find the volume by using the equation on the attachment. The formula is that volume equals one half times (base times height) times triangle height. Thank you for your help.
Hannah Answered by Penny Nom. 





Prealgebra volume of a prism 
20070510 

From Brenda: Find the volume of a triangular prism with a base of 5 cm by 5 cm and a height of 12.5 cm. Round to the nearest tenth. Answered by Stephen La Rocque. 





How many faces on a prism? 
20070510 

From Samad: How many faces does a rectangular prism have? Answered by Penny Nom. 





Names of solid figures 
20070328 

From Debbie: What is the name of the solid figure: 1) base with 5 equal sides and faces that are 5 triangles 2) all 6 faces are squares and 3) 2 congruent pentagons for bases and 5 rectangular faces. Please help! Thanks Answered by Penny Nom. 





The volume of a trough 
20070327 

From Tracy: I need help trying to find the volume of a 9 ft long trough that has two
equilateral triangles on the end. When the water of the trough is 2 feet
deep and its depth keeps increasing by 1/2 ft/minute. I have to figure
out at what rate the water is flowing into the trough.
Can you point me in the right direction for finding the equation
for the volume of the trough? Answered by Penny Nom. 





A triangular prism 
20070326 

From Tom: Hi, I need to find a container in the shape of a triangular prism that will fit
four table tennis balls (this is for a math project!). These balls have a
diameter of 4cm, so a radius of 2. I know that the formula for finding
an incircle from a triangle is: radius of incircle =
2area of triangle / perimeter of triangle
But I need to know the length of one side of the triangle from the incircle
(the triangle needs to be equalateral).
Can you help me find a formula for this?
Thanks so much!
Tom Answered by Penny Nom. 





How many hours will it take to fill completely? 
20070319 

From Leslie: If a rectangular prism measures 8" and measures 12" by 16", what is it's volume? If after 8 hours the prism is 6" full, how long will it take to fill and how many hours will it take to fill completely? Answered by Stephen La Rocque. 





Surface area of a triangular prism 
20070221 

From Katrina: What is the formula to finding the surface area of a triangular prism? Answered by Gabriel Potter. 





The surface area of a hexagonal prism 
20070219 

From Cari: How do you find the surface area of a hexagonal prism? Thank you. Answered by Penny Nom. 





The volume of a prism 
20070214 

From jasmine: What is the formula to find the volume of a triangular prism Answered by Penny Nom. 





a specific 3d shape 
20070212 

From Robby: What three dimensional shape has 6 vertices, 5 faces, and two congruent triangular bases? I can't find the answer to this question anywhere. Your help will be appreciated. Thanks, Robby Craig Answered by Pam Fowler, Gabe Potter and Walter Whiteley. 





The surface area of a triangular prism? 
20061029 

From Amanda: What is the formula for the surface area of a triangular prism? Answered by Haley Ess. 





Shapes 
20051112 

From Tonya and Hailey: MY THIRD GRADERS TEACHER HAS SENT HOME HOMEWORK ASKING FOR THEM TO FIND REALWORLD OBJECT IN MANY DIFFERENTS SHAPES A FEW HAVE US STUMPED Answered by Penny Nom. 





Surface areas 
20050511 

From Jessica: How can I demonstrate to my high school students the reason for the formulas for the surface area of a prism, right cylinder, and regular pyramid, and right cone? Answered by Penny Nom. 





Volume and surface area of a prism 
20050429 

From Melissa: Can you please tell me if the volume and surface area of a prism can ever be the same? Could you please explain why or why not. Answered by Walter Whiteley. 





Is a cylinder a type of prism? 
20040129 

From Rebecca: Is a cylinder a type of prism? Answered by Penny Nom. 





8 faces, 12 vertices, and 18 edges 
20030422 

From Thomas: I would like to know the proper name for this geometrical solid. It has 8 faces, 12 vertices, and 18 edges? Answered by Penny Nom. 





A rectangular prism 
20030109 

From Julie: How many faces on a rectangular prism and how many bases? Can the base also be a face and can a face also be a base? Answered by Diane Hanson. 





A triangular prism 
20021030 

From Daniel: I was wondering what a triangular prism was. Answered by Diane Hanson. 





A triangular prism 
20020428 

From A student: Need the formula for the surface area of a triangular prisim? Answered by Penny Nom. 





Prisms 
20010410 

From A fourth grade class: A fourth grade class is curious about the names that have been given to various solid geometric figures based on their shapes: are there names for solids based on a rhombus, a trapezoid, a parallelogram, a decagon, and/or a quadralateral? Answered by Chris Fisher. 





Volume and surface area of a cylinder and a triangular prism 
20010331 

From Kevin: I was wondering how do you find the volume and surface area of a cylinder and a triangular prism. Answered by Penny Nom. 





Triakis 
20010217 

From Anne Grant: I am a grade 8 teacher and have come across the term "Triakis" used with Tetrahedron, octahedron, and hexahedron. What does this term refer to, and what's the difference between a triakis polyhedron and one that is not? I'd also like to know what is meant by the term antiprism, as opposed to prism. Answered by Penny Nom. 





A prism 
20010118 

From Nigel Ayling: What is the mathematical definition of a prism, I am confused by the following definitions as they appear to be contradicto... Answered by Walter Whiteley. 





Pyramids and prisms 
20000118 

From Tyler: What's the definition of a Triangular Prism and a Triangular pyramid. Answered by Penny Nom. 





Un volume d'une capacité minimal 
20090105 

From Pauline: je doit faire un volume d'une capacité minimal de 2500 cm 3 en quell matiere que ce soit
* un prisme a base pentagonale non réguliere
* une sphere
* stella octangula Answered by PierreLouis Gagnon. 





l'armature d'un prisme 
20080301 

From dufetre: a l'aide d'une tige de 63cm on desire construire l'armature d'un prisme dont
la base est un triangle equilateral et dont la hauteur mesure 3cm de plus que la
la longueur du cote du triangle.
Soit x la longueur du cote du triangle.exprimer en fonction de x la hauteur de
ce prisme
exprimer en fonction de x la longueur totale des aretes
Quelle sera la longueur du cote du triangle.
merci Answered by Maxime Fortier Bourque et Thierry Moisan. 

