Find the radius of the circle inscribed in a triangle whose sides are ...
Step 1: Find the semi-perimeter of the triangle
- The semi-perimeter of a triangle is calculated by adding all three sides of the triangle and dividing by 2.
- In this case, the sides of the triangle are 8 cm, 15 cm, and 17 cm.
- The semi-perimeter, s, is given by s = (8 + 15 + 17) / 2 = 20 cm.
Step 2: Use Heron's Formula to find the area of the triangle
- Heron's formula states that the area of a triangle with sides a, b, and c and semi-perimeter s is given by the formula:
Area = √(s(s - a)(s - b)(s - c))
- Substituting the values, we get Area = √(20(20 - 8)(20 - 15)(20 - 17)) = √(20*12*5*3) = √(3600) = 60 cm².
Step 3: Use the formula for the radius of the inscribed circle
- The radius of the inscribed circle in a triangle with sides a, b, and c and area A is given by the formula:
Radius = A/s
- Substituting the values, we get Radius = 60/20 = 3 cm.
Therefore, the radius of the circle inscribed in the triangle with sides 8 cm, 15 cm, and 17 cm is 3 cm. Hence, the correct answer is option 'C'.