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Option 1 : 346.5
Given :
Area of rectangle = 273 cm2
The radius of circle = breadth of the rectangle
Formula used :
Area of rectangle = length × breadth
Area of circle = π r2
Solution :
Let the breadth of rectangle be x cm
∴ the length of rectangle = (2x + 5) cm
∴ x × (2x + 5) = 273
⇒ 2x2 + 5x = 273
⇒ 2x2 + 5x - 273 = 0
⇒ 2x2 + 26x - 21x - 273 = 0
⇒ 2x(x + 13) - 21(x + 13) = 0
⇒ (x + 13)(2x - 21) = 0
If x + 13 = 0
then x = -13 (breadth can't be negative)
If 2x - 21 = 0
then x = 21/2
Breadth of rectangle = (21/2) cm
Now, Breadth of rectangle = radius of circle
∴ r = 21/2 cm
Area of circle = π r2
⇒ Area of circle = (22/7)(21/2)(21/2)
Area of circle = 346.5 cm2
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