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Question
A circle with radius 16 cm is cut into four equal parts and rearranged to form another shape as shown in the following figure:
Does the perimeter change? If it does change, by how much does it increase or decrease?
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Solution
Radius of the circle = 16 cm
∴ Perimeter of the circle = 2πr = 2 × 16 × π = 32π cm
Now, the circle is rearranged into another shape such that A = B = C = D.
Perimeter of above shape = 27πr + 2r = (32π + 32) cm
Yes, the perimeter increases by (32π + 32 – 32π) = 32 cm
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