An incircle with center O is drawn inside an equilateral ΔABC, and the length of the side is 12 cm. Find the area (in sq.cm) of the triangle that is not in the incircle.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 24.64.
Radius (r) = (12/2√3) = 2√3 cm
Area of incircle = πr2 = π(2√3)2 = 12π ≈ 37.71 cm2 [π = 22/7]
Area of equilateral triangle = (√3/4) × (12)2 = 36√3 ≈ 62.35 cm2 [√3 ≈ 1.732]
Area outside incircle = 62.35 - 37.71 = 24.64 cm2
Hence, the area of the triangle that is not in the incircle is 24.64 cm2.