Solve triangle ABC given that a 20 b30 c40Solutiona 20 b30 c

Solve triangle ABC given that: a= 2.0, b=3.0, c=4.0.

a= 2.0, b=3.0, c=4.0

Apply cosine rule : cosA = (b^2 +c^2 - a^2)/2bc

cosA = (3^2 +4^2 -2^2)/2*3*4

A = 28.96 deg

Again use cosine rule:

cosC = (b^2 +a^2 - c^2)/2ab

=( 3^2 +2^2 - 4^2 )/2*2*3

C = 104.48 deg

B = 180 -A - C = 180 -28.96 -104.48 = 46.56 deg