Perpendicular cross section of a pyramid ------- triangle.
Imagine you cut pyramid like that. Height of pyramid would be height of your triangle. and sides of pyramid would be sides of triangle.
Perpendicular cross section of a cylinder ------- rectangle
diameter of a base of cylinder would be one side of rectangle and height of cylinder would be other side of rectangle. (pair of sides)
parallel cross section of a sphere ------ circle
when you cut sphere a side would apear with shape of circle.
shape create.... ----- cylinder.
one side of rectangle would be hight of cylinder and other would be radius of it.
last one is cone. If you place right angle in coordinate beginning (0.0) and one of shorter sides to lie on y axis other would be on x axis. when rotated you get cone.
