Answers:
- Answer for problem 12) Approximately 200.96 square inches
- Answer for problem 13) Approximately 150.72 inches
Each approximate value used pi = 3.14
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Explanations:
Problem 12
The larger circle has a diameter of 48 inches. Each smaller circle has a diameter of 48/3 = 16 inches because we have three identical smaller circles stacked on top of each other to exactly the height or diameter of the larger circle.
That 16 inch diameter cuts in half to 8 inches, which is the radius of any given smaller circle. We'll plug r = 8 into the area formula below to get the following result:
A = pi*r^2
A = 3.14*8^2
A = 200.96
This is the approximate area of one smaller circle. The value is approximate because pi = 3.14 is approximate. To get a more accurate answer, use more decimal digits of pi.
The units for the area are in "square inches" which we can write as "square in" or as "in^2".
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Problem 13
The diameter is d = 48 which is plugged into the circumference formula below
C = pi*d
C = 3.14*48
C = 150.72
The perimeter of the larger circle is roughly 150.72 inches
The circumference is the perimeter of the circle, i.e. the distance around the circle's edge.