Consider the solid formed by rotating a square about a line. Which statements are true? Select all that apply.
A) The solid is a cube.
B) The solid is a rectangular prism.
C) The solid is a cylinder.
D) The height of the solid is twice the width of the solid.
E) The diameter of the solid is twice the height of the solid.
OF) The diameter of the solid is equal to the height of the solid.



Answer :

Let's carefully analyze the process of rotating a square about a line and determine the properties of the resulting solid.

Consider a square with side length [tex]\( s \)[/tex]. When this square is rotated about one of its sides, we get a solid of revolution.

To identify the resulting solid, imagine rotating the square about one of its sides:

1. Rotating a square about one of its sides:
When the square rotates about one of its sides, it sweeps out a three-dimensional space.

This movement creates a cylinder. The height of this cylinder equals the side length of the square, and the radius of the cylinder also equals the side length of the square. The reason it's a cylinder and not a cube is due to the shape traced, which involves circular motion ending up forming cylindrical bases.

So far, we have established:

- The solid formed by rotating the square is a cylinder.

Now let's analyze each statement to verify its truth:

A) The solid is a cube.
- False. Rotating a square about its side does not produce a cube. A cube would have equal dimensions in all three directions, but this isn't the case here.

B) The solid is a rectangular prism.
- False. A rectangular prism has faces that are rectangles, not circles. This solid is not a rectangular prism.

C) The solid is a cylinder.
- True. As established, the rotation of a square about one of its sides results in a cylinder.

D) The height of the solid is twice the width of the solid.
- False. The height of the cylinder is equal to the side of the square, and the diameter is also twice the side length of the square. However, considering "width" as a dimension in a different direction might not apply accurately here.

E) The diameter of the solid is twice the height of the solid.
- True. The height of the solid (cylinder) is [tex]\( s \)[/tex], and the diameter (twice the radius) is [tex]\( 2s \)[/tex], which indeed is twice the height.

F) The diameter of the solid is equal to the height of the solid.
- False. The diameter of the cylinder is twice its height.

Based on the analysis:

The true statements are:
- C) The solid is a cylinder.
- E) The diameter of the solid is twice the height of the solid.