







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 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. 





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 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. 

