a = 9, b = 7, c = 8

The semi-perimeter s is 12.

s – a = 3

s – b = 5

s – c = 4

tan(A/2) = sqrt((5*4) / (12*3)) = sqrt(5)/3. A = 73.40deg.

tan(B/2) = sqrt((4*3) / (12*5)) = sqrt(5)/5. B = 48.19deg.

C = 180 – (A + B) = 58.41deg.

p=(27+21+24)/2

p=36

S=\sqrt{36(36-27)(36-21)(36-24)}

S=\sqrt{36(9)(15)(12)}

S=\sqrt{58320}

S=241,49….

cosA = (b^2+c^2-a^2)/2bc

cosA = (21^2+24^2-27^2)/(2*21*24) = 0.285714

A = arccos(.285714) = 73.39845 degrees

sinA/a = sinB/b = sinC/c

.035493 = sinB/21

SinB = .745356

B = arcsin(.745356) = 48.1897 degrees

SinC = 24*.035493 = 0.851835

C = arcsin(.851835) = 58.4119 degrees

Check 73.39 + 48.19+ 58.42 = 180 degrees okay

Area = .5absinC = 241.49