A circle has a radius of 5. What is its circumference? (Use pi is about 3.14.)

a.15.7

b.25.0

c.78.5

d.31.4

Explanation

Circumference equals 2 times pi times the radius. That is 2 times 3.14 times 5, which equals 31.4. The value 78.5 is the area, not the circumference.

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