1.What is the inradius of triangle ABC if side BA=BC=29 and if side AC= 42.
2.What is the circumradius ABC if side BA=BC=29 and if side AC= 42.
Inradius = r = Area / semi-perimeter
semiperimeter = (29 + 29 + 42) / 2 = 50 = s
Area = sqrt ( s (s -a) (s - b) (s -c) where a,b,c are the side lenghts
So
sqrt [ 50 (21)(21)(8) ] = 21 * 20 = 420
r = 420 / 50 = 42 / 5 = 8.4
circumradius = R = abc / ( 4 area) where a,b,c are the sides
abc = (29)(29)(42) = 35322
area (from other answer) = 420
4 * area = 1680
R = 35322 / 1680 = 21.025
