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3 February, 17:01

A circular mirror has a diameter of 12 inches.

Part A

What is the area, in square inches, of the mirror?

A. 6pi

B. 12pi

C. 36pi

D. 72pi

Part B

A circular frame that is 3 inches wide surrounds the mirror.

What is the combined area, in square inches, of the circular mirror and the frame?

A. 9pi

B. 18pi

C, 54pi

D. 81pi

Answers (1)
  1. 3 February, 17:57
    Part A

    C. 36π

    Part B

    D. 81π

    Step-by-step explanation:

    The general formula for the area of a circle is:

    A = πr², where 'r' represents the radius of the circle

    Since the mirror has a diameter of 12 inches, the radius is half of that measure, or 6 inches. So, for the area of just the mirror:

    A = π6² = 36π in²

    Adding a circular frame around the mirror increases the radius by another 3 inches:

    6 in + 3 in = 9 in

    Given the new radius, use the same formula to calculate the overall area:

    A = π9² = 81π in²
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