9514 1404 393
Answer:
30.85 in
Explanation:
The circumference of a circle with a 6" radius is ...
C = 2πr
C = 2π(6 in)
Then the curved portion of a semicircle with that radius will have the length ...
1/2C = 1/2(2π)(6 in) = 6π in . . . . curved length
The straight portion of the boundary of this figure is simply twice the radius, so is ...
2×6 in = 12 in . . . . straight length
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The perimeter is the sum of the curved and straight lengths:
P = (6π +12) in ≈ 30.8496 in ≈ 30.85 in . . . . figure perimeter