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प्रश्न
Area of a rectangle and the area of a circle are equal. If the dimensions of the rectangle are 14 cm × 11 cm, then radius of the circle is ______.
विकल्प
21 cm
10.5 cm
14 cm
7 cm
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उत्तर
Area of a rectangle and the area of a circle are equal. If the dimensions of the rectangle are 14 cm × 11 cm, then radius of the circle is 7 cm.
Explanation:
Given, dimensions of rectangle, l = 14 cm and b = 11 cm
According to the question,
Area of rectangle = Area of circle
⇒ l × b = πr2
⇒ `14 xx 11 = 22/7 xx r^2`
⇒ `r^2 = (14 xx 11 xx 7)/22` ...`[∵ π = 22/7]`
⇒ r2 = 49
⇒ r = `sqrt(49)`
⇒ r = 7 cm
Hence, the radius of circle is 7 cm.
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