a=5m , b=8m , c=7m

a^2= b^2+c^2-2bc Cos A

(5)^2= (8)^2+(7)^2-2(8)(7) Cos A

Cos A= 5^2-8^2+7^2/-2(8)(7)

Cos A= 10/-112

Angle A= -0.0898

Angle A= 95 Degrees 9 minutes

How to find other B & C angle?

This is what i work out but stuck.........

a/Sin A = b/SinB

5/Sin 95 Degrees 9 minutes = 8/Sin B

Sin B = (8)(Sin 95 Degrees 9 minutes)/5

Sin B = 1.5939

Problem is i calculate using sin^-1...

Thanks much