







An arch in the form of a semiellipse 
20200420 

From Anggelica: an arch in the form of a semiellipse is 8 feet wide at the base and has a height of 4ft. how wide is the arch 1foot above the base? Answered by Penny Nom. 





A semi ellipse 
20170725 

From Ian: The arch of the bridge is in the shape of semi ellipse,with its major axis at the water level.suppose the arch is 20ft. High in the middle,and 120 ft. Across its major axis. How high above the water level is the arch,at a point 20 ft.from the center (horizontally). Round of 2 decimal places Answered by Penny Nom. 





A cone with an oval as a base 
20110803 

From Emily: Hi, I was wondering how to calculate the surface area of a cone with an oval as a base (which I think is referred to as an elliptic cone or something like that). I have the both the maximum and minimum radius as well as the height, but I don't have a slant height and I'm not sure how to calculate it and then calculate surface area. I would really appreciate some help. Thanks! Answered by Robert Dawson. 





The volume of a smokestack 
20110113 

From tom: The outer protective smokestack of a steamship is streamlined so that it has
uniform oval section parallel to the deck. The area of this oval section is
48 sq. ft . If the length of the stack is 15 ft. and the stack is raked aft so
that its axis at its upper end is horizontally 4.2 ft from the lower end, find
the volume enclosed by the stack. Answered by Penny Nom. 





Elliptic space 
20090918 

From Htet: What is elliptic space and geometry? Answered by Robert Dawson and Chris Fisher. 





A sundial on an elliptical cylinder 
20090722 

From Leo: I want to build a sundial where the shadow falls on an elliptical cylinder. I can
calculate the coordinates of the points on the cylinder that I want to mark.
My problem is that I will have to make the surface as a flat sheet and bend it
into an elliptical shape. However, I cannot work out a scheme to transfer
the coordinates I know into a distance that will work when I bend the shape.
Help! Answered by Robert Dawson. 





Can't find circumference of an ellipse 
20070706 

From Michele: I need to figure the circumference of an oval and I know the height and width. Answered by Penny Nom. 





Elliptic trigonometry 
20050915 

From Krystal: I'm currently searching for a science project topic and i have the idea of deriving elliptic trigonometry analogous to circular trigonometry. My questions are:
Is this project "possible" to do? Answered by Chris Fisher and Harley Weston. 





Quadratics 
20050105 

From Usman: Hi, in my Grade 11 Functions math class we have been assigned the task of finding jobs and careers related to quadratics, I have done many searches but have been unsuccessful, then I saw your website and emailed. I also have to use an example of a math problem that the job uses, then solve it, this will all compile on bristol board for a presentation. I would greatly appreciate it if you could send me some links and references of sources that refer to this subject. Answered by Harley Weston. 





An elliptical table 
20050103 

From Roger: Want to make an elliptical table, say the long (major) axis is 4 feet, and the short (minor) axis is 3 feet. I can construct this figure, but I'm trying to figure out what the exact dimension of a rectangle within this ellipse will be if I make the table a drop leaf type where the drop dimensions are equal for each end of both the long and short axes. Intuitively, it looks like there is one and only one solution. Answered by Penny Nom. 





An elliptic cone 
20040224 

From Ben:
I am building a model for my architecture class. I need to build a elliptic cone out of chipboard and i have no idea how to do this.
The cone needs to be 20in tall and the ellipse has a max radius of 10in and a min radius of 8in.
So my question is how do i lay this out on a piece of paper so that i can form the cone after i cut it out.
Answered by Penny Nom. 





An elliptical race track 
20031216 

From Judy: the inner rail of a race track is a perfect ellipse. the track is a standard width all the way around. how can i prove that the outer rail is a ellipse? Answered by Penny Nom. 





Noneuclidean geometry 
20031208 

From Geoffrey: How can you use noneuclidean geometry to navigate on a sphere? What geometers did work in this area? Answered by Chris Fisher. 





Arclength of an ellipse 
20010703 

From A hobbyist: What is the equation (with the length of the arc as a variable) for one quadrant of the ellipse,... Answered by Claude tardif. 





An elliptic tunnel 
20010324 

From Janna: A tunnel is built under a river for a road 12m wide with a 2m sidewalk on either side. The top of the tunnel is semielliptical. A local bylaw stipulates that there must be a clearance of at least 3.6m at all points on the road. If the smallest possible ellipse is used, find the clearance at the center of the road. Answered by Harley Weston. 

