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Question
The radii of two concentric circles are 19 cm and 16 cm respectively. The area of the ring enclosed by these circles is
Options
320 cm2
330 cm2
332 cm2
340 cm2
Solution
330 cm2
Let ;
R = 19 cm and r = 16 cm
Thus, we have ;
Area of the ring = π(R2 - r2)
= π (R + r) (R - r)
`= |22/7xx(19+16)xx(19-16)|"cm"^2`
`=(22/7xx35xx3)"cm"^2`
= 330 cm2
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