Question

If the label of a can of yams were cut off and laid flat, which expression would give the area, A, of the label with the measurements shown?

A.) A = π • r2 • h

B.) A = π • r • h

C.) A = 2 • π • r • h

D.) A = 2 • r • h

Answer 1

A=2⋅π⋅r⋅h

Explanation:

Answer 2

C.) A = 2 • π • r • h

Explanation:

The distance around a circle is the circumference, and the formula for it is

C = 2πr.

Taking the label off of the can and stretching it out makes this distance around the circle the length of the rectangular label.

To find the area of a rectangle, we multiply length and width; we know the length is 2πr. The width of the rectangle is the height of the can; this makes the area

A = 2πrh.