Question

In a triangle ABC, if a=18 , b=24, c=30 find sinA, sinB ,sinC.

Answer 1

law o' cosines

Answer 2

\[a^2=b^2+c^2-2bc\cos(A)\]
\[\cos(A)=\frac{b^2+c^2-a^2}{2bc}\]
\[A=\cos^{-1}\left(\frac{b^2+c^2-a^2}{2bc}\right)\]