Question

Using the formula C = 2πr, find the circumference of a circle with diameter of 28 inches.

a. 56 in.
b. 28 in.
c. 88 in.
d. 44 in.

Answer 1

88 in

Explanation:

Answer 2

`Hmm...\ and\ use\ \pi\approx(22)/(7)\ \ \ ;)\\\\the\ diameter\ (d):d=2r\\\\therefore:\ d=28\ in\to2r=28\ in\ \ \ |divide\ both\ sides\ by\ 2\\\\r=14\ in\\--------------\\The\ formula:C_O=2\pi r\ where\ r=14\ in\ and\ \pi\approx(22)/(7)\\\\subtitute:\\\\C_O\approx2\cdot(22)/(7)\cdot14=2\cdot22\cdot2=88\ (in)\\\\\huge\boxed{C_O=88\ in.}\leftarrow\boxed{c.}`