A circle is inscribed in an equilateral triangle of side 12 cm. The area of the region between the triangle and the circle is approximately
- 50 sq cm
- 15 sq cm
- 32 sq cm
- 25.04 sq cm
Show answer and solution
Correct answer: D. 25.04 sq cm
1. Triangle area = (square root of 3)/4 × 144 ≈ 62.35 sq cm.
2. Incircle radius = side/(2 (square root of 3)) ≈ 3.464; area ≈ pi × 12 ≈ 37.71 (incircle).
3. Difference ≈ 62.35 - 37.71 ≈ 24.64 → option ≈ 25 sq cm.
_Source: syllabus Mathematics, Ch 11 "Areas Related to Circles", §11.2_