A pavement is tiled in the shape of a triangle with area 84 cm² and a semi-perimeter of 21 cm. What is the radius of the circle that fits perfectly inside the triangle (inradius)?
Show answer & explanation
Correct answer: A
Explanation
given :
Area (A) = 84 cm²
Semi-perimeter (s) = 21 cm
According to the formula:
Area of triangle = r × s
84 = r × 21
r = 84 ÷ 21
r = 4
inner radius = 4 cm