+128399 OK we have this
6 + b + c = 18
b + c = 18 - 6
b + c = 12 (1)
Also
6^2 + b^2 = c^2 [ Pythagorean Theorem ]
36 + b^2 = c^2
36 = c^2 - b^2
36 = ( c - b) ( c + b) sub in (1) for b + c
36 = (c - b) ( 12) divide both sides by 12
3 = c - b rearrange as
b = c - 3 sub this into (1) for b
c - 3 + c = 12
2c = 15
c =7.5
