Question

Which is the length of HJ expressed in terms of pi?

A. 3/10 pi
B. 9/20 pi
C. 11/20 pi
D. 81/20 pi

Answer 1

B. 9/20
`\pi`

Explanation:

the circumference is 2
`\pi`r. Since the radius is one, that would be 2
`\pi`.

81/360=0.225, or 22.5% of the circumference. 22.5% of 2
`\pi` is 0.45
`\pi`. 0.45=9/20, so the answer is B.

CHECK: 2
`\pi` = 6.283

6.283x0.225=0.14137, or 9/20
`\pi`