Answer: C) 17.9 inches
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Explanation:
A full circle of radius 5 inches would have a perimeter or circumference of...
C = 2*pi*r
C = 2*3.14*5
C = 31.4
This value is approximate because pi = 3.14 is approximate.
The distance around a full circle with radius 5 inches is roughly 31.4 inches, but we only want a quarter of this. Therefore, the distance around the curved portion of the quarter circle is roughly C/4 = (31.4)/4 = 7.85 inches.
Choice A would be the answer if your teacher only cared about the curved portion. However, don't forget about the straight line portions that also make up the quarter circle. Choice A might have been put there as a trick answer.
We'll add on the two copies of the radius 5 inches to get a total perimeter of 5+5+7.85 = 10+7.85 = 17.85 = 17.9 inches, which points to choice C as the answer.
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Side note:
If we used a more accurate version of pi, say the version stored in your calculator, then the perimeter is roughly
5+5+(2*pi*5)/4 = 17.8539816339744
Rounding to the nearest tenth leads to the same answer of 17.9 inches
