Question

A cylindrical rod measures 10 inches long and the circumference of one of its bases is 8π inches. The rod is cut into two equally-sized pieces and then all surfaces are painted.

What is the area that is painted?

Use π≈3.14.

Enter your answer, rounded to the nearest tenth, in the box.

in²

Answer 1

see below

Explanation:

length = 10

circumference = 2πr = 8 π, so r=4

8π=25.12

cut half so length = 5, so lateral surface = 8π*5 = 40π =125.6

top circle area = πr² = 3.14*4² = 3.14 *16 = 50.24

top & bottom = 2*50.24 = 100.5

so total surface of EACH after cut in half = 100.5+125.6 =226.1

TWO of them = 2*226.1 =452.2