Match the term to the definition.
perpendicular cross section of a pyramid
perpendicular cross section of a cylinder
parallel cross section of a sphere
shape created when a rectangle is rotated about the y–axis
shape created when a right triangle is rotated about the y–axis
a) rectangle
b) triangle
c) circle
d) cone
e) cylinder

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.

He will need 2,898 pieces of paper

For a 0.25 pfor b o.3pp (0.25+0.3)=0.28