Coordinate Geometry Answer 3

Coordinate Geometry Answer 3:

3. If a circle has a diameter of 12, what is the circumference of the circle?

A. 6 p

B. 12 p

C. 24 p

D. 36 p

E. 144 p

The correct answer is B.

Here is the formula for the circumference of a circle:

circumference = radius ´ 2 ´ p

This circle has a diameter of 12, and since radius is always half of diameter, its radius is 6.

So now we can substitute values into the formula:

circumference = radius ´ 2 ´ p
circumference = 6 ´ 2 ´ p
circumference = 12p

REMEMBER: Don't confuse the formula for the circumference of a circle with the formula for the area of a circle:

circle area = radius² ´ p

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