Question

The radius of a circle with an area of 60 square centimeters is represented by the expression StartRoot StartFraction 60 Over pi EndFraction centimeters. What is another way of expressing the radius?

2 StartRoot 15 pi EndRoot
4 StartRoot 5 pi EndRoot
StartFraction 2 StartRoot 15 pi EndRoot Over pi EndFraction
StartFraction 4 StartRoot 5 pi EndRoot Over pi EndFraction

Answer 1

c

Explanation:

Answer 2

• C) StartFraction 2 StartRoot 15 pi EndRoot Over pi EndFraction

Explanation:

Given circle with area of:

• A = 60 cm²

Find its radius

• A = πr² ⇒ A/π = r² ⇒ √(A/π) = r ⇒ r = √(A/π)

Substitute the values and find the value of r:

• r = √(60/π) = 2√(15/π) = 2√(15π) / π

Now compare this with answer choices:

• A) 2 StartRoot 15 pi EndRoot ⇒ 2√(15π), incorrect

• B) 4 StartRoot 5 pi EndRoot ⇒ 4√(5π), incorrect

• C) StartFraction 2 StartRoot 15 pi EndRoot Over pi EndFraction ⇒ 2√(15π) / π, correct

• D) StartFraction 4 StartRoot 5 pi EndRoot Over pi EndFraction ⇒ 4√(5π) / π, incorrect