sat suite question viewer
A cylinder has a diameter of inches and a height of inches. What is the volume, in cubic inches, of the cylinder?
Explanation
Choice C is correct. The base of a cylinder is a circle with a diameter equal to the diameter of the cylinder. The volume, , of a cylinder can be found by multiplying the area of the circular base, , by the height of the cylinder, , or . The area of a circle can be found using the formula , where is the radius of the circle. It’s given that the diameter of the cylinder is inches. Thus, the radius of this circle is inches. Therefore, the area of the circular base of the cylinder is , or square inches. It’s given that the height of the cylinder is inches. Substituting for and for in the formula gives , or cubic inches.
Choice A is incorrect. This is the area of the circular base of the cylinder.
Choice B is incorrect and may result from using , instead of , as the value of in the formula for the area of a circle.
Choice D is incorrect and may result from using , instead of , for the radius of the circular base.