Question

question 15 (multiple choice worth 4 points)
(06 04 lc)
if a rectangle was rotated about the y - axis, like the one shown below, what would be the resulting three - dimensional shape?
○ cone
○ cylinder
○ pyramid
○ sphere

Explanation:

Step1: Recall the properties of 3D shapes formed by rotation

When a rectangle is rotated about one of its sides (in this case, the y - axis), we consider the shape formed.

• A sphere is formed by rotating a semicircle.
• A pyramid is not formed by rotating a rectangle. A pyramid has triangular faces and a polygonal base.
• A cone is formed by rotating a right - triangle.
• A cylinder is formed by rotating a rectangle about one of its sides. When the rectangle is rotated about the y - axis, the two circular bases are formed by the rotation of the two opposite sides of the rectangle parallel to the x - axis, and the lateral surface is formed by the rotation of the sides parallel to the y - axis.

Answer:

C. Cylinder