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An equilateral triangle is inscribed in a circle. Select the option that indicateshow many times is the area of circle with respect to the area of triangle. |
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Answer» Answer: ⇒ Here, AB=BC=AC=12cm ⇒ Let OP=OR=OQ=r ⇒ We have O as the INCENTER and OP,OQ and OR are equal. ⇒ ar(△ABC)=ar(△OAB)+ar(△OBC)+ar(△OCA) 4 3
×(SIDE) =( 2 1
×OP×AB)+( 2 1
×OQ×BC)+( 2 1
×OR×AC) ⇒ 4 3
×(12) 2 =( 2 1
×r×12)+( 2 1
×r×12)+( 2 1
×r×12) ⇒ 4 3
×(12) 2 =3( 2 1
×12×r) ∴ r= 18 36 3
∴ r=2 3
cm ⇒ Area of the shaded region = Area of △ABC - Area of circle. ⇒ Area of the shaded region = 4 3
×(12) 2 − 7 22
×(2 3
) 2
⇒ Area of the shaded region =(62.35−37.71)cm 2 =24.64cm 2 |
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