What is the measure of the radius of the circle inscribed in a triangle whose sides measure 8, 15 and 19 units?  Choices: A) 2.8 units B) 6 units C) 3 units D) 5 units E) 12 units

Rationale: "sides are 8 , 15 and 19 . . . thus it is right angle triangle since 19 ^ 2 = 8 ^ 2 + 15 ^ 2 therefore , area = 1 / 2 * 15 * 8 = 60 we have to find in - radius therefore , area of triangle = s * r . . . . where s = semi - perimeter and r = in - radius now s = semi - perimeter = 19 + 15 + 8 / 2 = 21 thus , 60 = 21 * r and hence r = in - radius = 2.8 option a"
Answer: A