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The Perimeter of a Semicircular Plate is 108 Cm. Find Its Area - Mathematics

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प्रश्न

The perimeter of a semicircular plate is 108 cm. find its area. 

बेरीज
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उत्तर

The perimeter of a semi-circular plate = 108 cm
⇒ πr + 2r = 108                 ...(r is radius of a circle )
⇒ r ( π + 2 ) = 108

⇒ r = ` (108)/( π + 2) = (108)/(22/7 + 2)  = (108 xx 7) / (36) = 21 "cm"`

Now, area of a semi-ccircular pleate = `[πr^2]/2   = [22/7 xx 21 xx 21]/2  = 693 "cm"^2` 

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पाठ 20: Area and Perimeter of Plane Figures - Exercise 20 (D) [पृष्ठ २६३]

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सेलिना Concise Mathematics [English] Class 9 ICSE
पाठ 20 Area and Perimeter of Plane Figures
Exercise 20 (D) | Q 7 | पृष्ठ २६३

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