an isosceles triangle with sides 13 13 10 and there is a circle inscribed it .find the radius of circle?  Options.
A) 1.32  B) 3.33  C) 3.58  D) 4.34  E) 5.18

Rationale: height of triangle = √ ( 13 ^ 2 - ( 10 / 2 ) ^ 2 ) = 12 area of triangle = r * s where , r = radius of inscribed circle & s = ( a + b + c ) / 2 area of triangle = 1 / 2 * b * h = 1 / 2 * 10 * 12 = 60 s = ( 13 + 13 + 10 ) / 2 = 18 r = area of triangle / s = 60 / 18 = 10 / 3 = 3.33 answer : b
Answer: B