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Question
If the perimeter of a semi-circular protractor is 36 cm. Find its diameter.
Solution
Let r cm be the radius of the protractor, then
Perimeter = πr + 2r
According to the question,
⇒ 36 = πr + 2r
⇒ 36 = r `( 22/7 + 2)`
⇒ r = 7 cm.
∴ The diameter of the protractor is ( 2 x 7) cm = 14 cm.
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