Question

Determine the missing parts of triangle $ABC$ from the given information.
$a=7,b=24,c=26$

Answer 1

We know $\cos A=\frac{b^2+c^2-a^2}{2bc}=\frac{1203}{1248}=0.964$
$\Rightarrow A=arc\cos \left(0.964\right)=15.42$ degrees
$\Rightarrow \cos B=\frac{a^2+c^2-b^2}{2ac}=\frac{149}{364}=0.41$
$\Rightarrow B=arc\cos \left(0.41\right)=65.8$ degrees