In Example 2, if the radius is halved and the height is doubled, what is the volume?

Data from Example 2

Answer the given questions about the indicated examples of this section.

How many square centimeters of sheet metal are required to make a protective cone shaped cover if the radius is 11.9 cm and the height is 10.4 cm? See Fig. 2.120. To find the total surface area using Eq. (2.24), we need the radius and the slant height s of the cone. Therefore, we must first find s. The radius and height are legs of a right triangle, and the slant height is the hypotenuse. To find s, we use the Pythagorean theorem:

Now, calculating the total surface area, we have

Thus, 1040 cm² of sheet metal are required.

s = r + h s = r + h2 11.92 +10.4 15.8 cm