pic: Measure Thrice

[Greg Ross]

Originally Posted by Richard

GW is right. The curved edge is elliptical, not parabolic. Referring again to the the mathworld site, an ellipse is a section through a cylinder (a circle is the special case in which the section plane is perpendicular to the cylinder's axis), while a parabola is a conic section (section through a cone).

Correct. Specifically, a parabola is the special case where the section plane is parallel to one "edge" of the cone, so that the curve never closes on itself: http://mathworld.wolfram.com/ConicSection.html

[John Gutmann]

If you make this like the way everyone else is wouldn't there me more lines on the triangle? They wouldnt be hidden lines because they are outside of the projection of the triangle face.