r = (ac + bc - ab)/2, r = (17 - ab)/2, 2r = 17 - ab, ab = 17 - 4 = 13.
аc + вc = 17 и аc^2 + вc^2 = 169, ac = 12, вc = 5. S = ac*вc/2, S = 12*5/2 = 30.
r = (ac + bc - ab)/2, r = (17 - ab)/2, 2r = 17 - ab, ab = 17 - 4 = 13.
аc + вc = 17 и аc^2 + вc^2 = 169, ac = 12, вc = 5.
S = ac*вc/2, S = 12*5/2 = 30.