Question

a=25.79, b=21.38, c= 19.02
Find the measure of angles A,BC

I can not get this one correct.....I found out that A = 79.10. I keep getting the math wrong for the B and C angles using the law of cosines as instructed.

Please help

Answer 1

c^2=a^2+b^2-2*a*b*cos(gamma);
gamma=arccos((a^2+b^2-c^2)/(2*a*b))=arccos((25.79^2+21.38^2-19.02^2)/(2*25.79*21.38));
a^2=b^2+c^2-2*b*c*cos(alpha);
alpha=arccos((c^2+b^2-a^2)/(2*c*b))=arccos((19.02^2+21.38^2-25.79^2)/(2*19.02*21.38));
b^2=a^2+c^2-2*a*c*cos(beta);
beta=arccos((a^2+c^2-b^2)/(2*a*c))=arccos((25.79^2+19.02^2-21.38^2)/(2*25.79*19.02));

alpha=79.1036 degrees;
beta=54.4942 degrees;
gamma=46.4022 degrees.