







The diagonals of a polygon 
20160129 

From Sofia: What are diagonals and if you drew an octagon and drew all the diagonals how many would there be? Please explain because this is pretty confusing! Thank you! Answered by Harley Weston. 





The diagonals of a cube 
20161202 

From Peter: when u have a cube and the inner diagonal is 41.6 how long is the outside diagonal Answered by Penny Nom. 





The diagonal of a 10 acre square 
20160411 

From Derrick: I own 100 acre square of land. I want to run from farthest corner of property to farthest corner, Diagonally. How many miles would I have traveled? Answered by Penny Nom. 





The diagonal of a rhombus 
20151114 

From Om: In a rhombus ABCD, angle A=60° and side AB=6 cm. Then diagonal BD is ? Answered by Penny Nom. 





The diagonals of a cube 
20140904 

From Rukshanth: How many diagonals does a cube have? Answered by Harley Weston. 





Intersection points and diagonals 
20130911 

From Kenneth: I was wondering, is there a relationship between the number of sides of a regular ngon and the number of times its diagonals intersect?
Ie:
4 sides=1 intersect (center, diagonals form an 'X' )
5 sides=5 intersects (diagonals form a star)
6 sides=13 intersects
And so on. Answered by Chris Fisher. 





The diagonals of a parallelogram 
20110217 

From ginger: Find the diagonals of parallelogram where the the side is 40 and the bottom side is 15. Answered by Penny Nom. 





Sides and diagonals of a polygon 
20101125 

From nicky: The sum of sides of two polygons is 12 and the sum of their diagonals is 19. What kind of polygon are they? Answered by Penny Nom. 





The diagonals of a rectangle 
20100330 

From Tabatha: The diagonals of a rectangle are 8 units long and intersect at a 60 degree angle. Find the dimensions of the rectangle. Answered by Penny Nom. 





A diagonal of an octagon 
20100302 

From cody: I have an octagon 3ft tall by 3ft wide. What are the lengths of the diagonal lines to the vertical and horizontal lines (b and b)? Answered by Penny Nom. 





Loading a headboard in a uhaul 
20100120 

From gina: I have a uhaul 9'10" long 4"9"wide 4'7"height I have a headboard 74 inches in height would it fit the box diagonally Answered by Penny Nom. 





Polygons, diagonals and the sum of the measures of the angles 
20091218 

From jason: find the set of polygons in which the number of diagonals is greater than the sum of the measures of the angles Answered by Robert Dawson. 





A diagonal of a rectangle 
20090701 

From Ruben: Please assist me with the following problem: A rectangle has a diagonal that is 3.6 feet longer than the length and 7.1 feet longer than the width. What are the dimensions of the rectangle? Thanks Answered by Harley Weston. 





The sides of a parallelogram 
20090317 

From Sami: If ABCD is a parallelogram, prove that line AB is congruent to line CD. Clearly state your reasons and conjectures. Answered by Penny Nom. 





A walkway through a park 
20090307 

From felicia: a diagonal walkway through a park is 18 meters long. If the park is a square, how long is one of its sides to the nearest tenth of a meter? Answered by Penny Nom. 





A shape with 10 sides 
20090303 

From Sandra: One of my son's math questions is as follows:
Suppose I have a shape with 10 sides. I choose a vertex then draw lines to the other vertices that dont share sides with the first vertex. How many vertices will that be and why? Answered by Penny Nom. 





Diagonals of a polygon 
20090216 

From Julie: How many diagonals can be drawn from one vertex in a 12sided polygon? Answered by Leeanne Boehm. 





A chord 
20090101 

From Deepa: Why in a circle,a chord is called as the longest diameter?
(A chord does not passes through the centre of the circle but a diameter passes through the centre) Answered by Penny Nom. 





The diagonals of an isosceles trapezoid 
20081114 

From hazel: how to solve the diagonals of an isosceles trapezoid? what is the formula? Answered by Harley Weston. 





A square with diagonal 200 metres 
20080820 

From kelvin: find the are and perimeter of a square with diagonal of 200 meters? Answered by Penny Nom. 





Perimeter, area and diagonals of a rectangle 
20080403 

From jenea: I have to find the perimeter as well as the area of a rectangle when given the diagonals are 12 units long and they intersect at a 60 degree angle. how do i find both the area and perimeter; do i use the 30 60 90 triangle rule? Answered by Stephen La Rocque and Penny Nom. 





The diagonals of a hendecagon 
20080310 

From karan: How many diagonals does a hendecagon have? Answered by Penny Nom. 





A line drawn between 2 vertices 
20080226 

From Arshad: what is a line drawn between 2 vertices which are not next to each other called. Answered by Penny Nom. 





The diagonal of a rectangle 
20080221 

From tim: is there a formula for finding the diagonal of a rectangle? Answered by Penny Nom. 





The diagonal of a cube 
20080210 

From Praveen: Given a Cube's diagonal, how does one find the edge of the cube. Answered by Stephen La Rocque. 





The width of a rectangle is 4 less than twice its length. 
20080209 

From Shawn: The width of a rectangle is 4 less than twice its length. If the area of the rectangle is 72 cm,
what is the length of the diagonal Answered by Stephen La Rocque. 





Cantor's diagonal argument 
20080126 

From David: Cantor's theory using a diagonal across a list of real numbers to proven uncoutability has always puzzled me.First in base ten, it feels like hocus pocus so I began thinking of the Boolean numbers as truer representations of place value (on,off). Secondly his list was always arbitrary or so I recollect. Therefore, I suggested using a seriesA=.10000....,B=.01000. C=.11000, etc.
Any diagonal is already located among the numbers listed. My only alteration is that since the final digit is always unrepresentably either one or zero, but it must be one or the other, I make an assumption that if x= .abc...1 and y= .abc...2 the only two possibilities and I choose to count F=x+y then then the numbers are countable= Z=sumFi,where I=2+2^2+2^3...
I hope this sketch is enough description, I asked Rudy Rucker more formally but got no mathematical response, someone else gave me some tale about slippery epsilon. What do tyou think of recasting his proofs in more rigorous form?
David French Answered by Claude Tardif and Walter Whiteley. 





A line between 2 vertices 
20071028 

From robert: what do we call a line between 2 vertices which are not next to each other Answered by Walter Whiteley. 





The diagonal of a square 
20070923 

From Nasreen: A(7,2) and C(1,4) are two vertices of a square ABCD
find in the form ax+by=c the equation of the diagonal BD Answered by Stephen La Rocque. 





A rectangular sheet of paper is folded along the diagonal 
20070901 

From Amit: A rectangular sheet of a paper with dimensions a and b is folded
along its diagonal. What is the area of the overlapped region? Answered by Harley Weston. 





Diagonals on a cylinder 
20070810 

From John: I have a cylinder that is 37.5" width X 25.25" circumference. I need to create a repeating diagonal lined pattern on the cylinder so that when it prints it joins perfectly at the circumference repeat. The design must follow these specs.
Black diagonal lines need to be 1.250" max width X 1.5" max spacing between the black lines.
Please Help Answered by Stephen La Rocque. 





How many diagonals does a polygon have? 
20070718 

From Edna: how do you find the numbers of diagonals of a polygons? Answered by Stephen La Rocque. 





a^2 + b^2 = c^2 
20070304 

From Colburn: 27 feet long base 14 feet height what is the diagonal Answered by Stephen La Rocque. 





Diagonals of a rectangular grid 
20070221 

From matthew: in a rectangular grid 3600x288 (or any large rectangle with an even number of units) how can I determine the number of vertices a diagonal line will pass through? Answered by Stephen La Rocque and Penny Nom. 





How many diagonals does a hexagon have? 
20070203 

From Marsha: How many diagonals does a hexagon have? Answered by Stephen La Rocque. 





The diagonals of a parallelogram are mutually bisecting 
20070121 

From Greta: I am having trouble proving that the diagonals of a parallelogram are mutually bisecting. Answered by Penny Nom. 





Can you characterize ALL polygons by the number of diagonals it has? 
20061217 

From Katie: Can you characterize ALL polygons by the number of diagonals it has? Answered by Penny Nom. 





The diagonals of a trapezoid 
20051111 

From Chris: Is there ever a case where the diagonals of a trapezoid bisect each other? Answered by Walter Whiteley. 





The diagonals of a hexagon 
20050815 

From Brittany: are all of diagonals in a hexagon has same length Answered by Penny Nom. 





A line segment connecting two vertices of a polygon 
20050202 

From James: What is a line segment (not a side) connecting two vertices of a polygon called? Answered by Penny Nom. 





Probability 
20041204 

From A parent: Consider a 30 sided polygon. If three diagonal are selected at random, what is the PROBABILITY that they share a common endpoint? Answered by Denis Hanson. 





Diagonals in a regular dodecahedron 
20040515 

From Joshua: A dodecahedron has twelve faces, all of which are regular pentagons. Three edges meet at each vertex of the dodecahedron. An interior diagonal is a segment connecting two vertices such that the segment is not an edge or along a face of the dodecagedron. How many interior diagonals does a regular dodecahedron have? Answered by Penny Nom. 





Diagonals in an octagon 
20031113 

From Glenn: Question 1. What is the probability of choosing the longest diagonal in an octagon? Question 2. Probability of choosing the shortest? Answered by Andrei Volodin and Penny Nom. 





Diagonals in an octagon 
20030804 

From Amanda: How many diagonals are in an octagon??? What would be a drawing of those diagonals??? Answered by Penny Nom. 





Diagonals in a polygon 
20020410 

From Murray: If you have a regular polygon with n sides and you draw all (n3)n/2 diagonals how many intersection will they form with each other and how many sections will they devide the polygon into. Answered by Caude Tardif and Chris Fisher. 





The diagonal 
20010328 

From Candace: Building measuring 40 feet 3 inches by 50 feet 3inches What is the measurement of the diagonal of the building? What was method of obtainin answer? Answered by Andrei Volodin. 





order 4+ determinants 
19991206 

From Joe Kron: Why is it never shown how to calculate the value of 4x4 (or larger size) deteminants by the diagonal multiply methods that are generally shown for 2x2 and 3x3 determinants? The method I'm talking about is called Cramer's Rule??? Is this method not extensible to order 4+ and if not why not? Anyway the method always shown for order 4+ is called "reduction by minors" which is not the answer to this question. Answered by Walter Whiteley. 

