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Find the area of the shaded region: - Mathematics

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Question

Find the area of the shaded region:

Sum
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Solution

Let radius of smaller circle be r and bigger circle be R

From the figure, r = `7/2` cm and R = `7/2 + 7 = 21/2`cm

∴ Area of shaded region = Area of bigger circle – Area of smaller circle

= πR2 – πr2

= π(R2 – r2)

= `π(21/2 xx 21/2 - 7/2 xx 7/2)`

= `π(441/4 - 49/4)`

= `22/7 xx 392/4`

= 308 cm2

Hence, the area of shaded region is 308 cm2.

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Chapter 9: Perimeter and Area - Exercise [Page 287]

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NCERT Exemplar Mathematics [English] Class 7
Chapter 9 Perimeter and Area
Exercise | Q 98. | Page 287

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