Question

Marcus and three of his friends are guessing the radius of a circular pond. They read that the circumference is 157 ft, so they can use the equation 3.14*2r=157 to determine which of these guesses which form the replacement set {20,25,30,35} is correct?.

What is the radius of the pond?

A. 20ft
B. 25ft
C. 30ft
D. 35ft

Answer 1

Option B. 25 ft

Explanation:

we know that

The circumference of a circle is equal to

`C=2\pi r`

we have

`C=157\ ft`

assume

`\pi =3.14`

substitute in the formula

`157=2(3.14)r`

Solve for r

Divide by 2(3.14) both sides

`r=157\(2(3.14))`

`r=25\ ft`