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What is the area of a circle that has a circumference of 42 inches ?

What is the area of a circle that has a circumference of 42 inches ?-example-1
User Jammer
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1 Answer

4 votes

Answer:

D. 140.4 in²

Explanation:

We are given the circumference. The formula for circumference is

C = πd where d is the diameter and C is the circumference.

We are given C = 42, so we have...

42 = πd

Solving for d gives us...

42/π = d

The formula for area of a circle is

A = π(r²) where A is the area, and r is the radius

The radius is half of the diameter, so we divide 'd' by 2 to get the radius...

r = d/2 = (42/π)/2 = 21/π

The area of the circle is...

A = π(21/π)²

A = π(441/π²)

A = 441/π

A = 140.3746598

A = 140.4 in²

User Antoine Grenard
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