Question

In triangle abc, if A=120 degrees, a=8 and b=3, then angle B=

Answer 1

The angle of B is $\angle B=19^{\circ}$

Explanation:

It is given that $\angle A=120^{\circ}$ and $a=8, b=3$

To determine the $\angle B$, let us use the law of sine formula.

Thus, we have,

$\frac{Sin A}{a} =\frac{Sin B}{b}$

Substituting the values in the formula, we have,

$\frac{Sin 120}{8} =\frac{Sin B}{3}$

Multiplying both sides by 3,we get,

$\frac{3(0.866)}{8} ={Sin B}$

Simplifying and dividing, we get,

$0.32475=Sin B$

Multiplying both sides by $\sin ^{-1}$, we get,

$\sin ^{-1}(0.32475)=B$

Thus, $B=18.95^{\circ}=19^{\circ}$

Hence, The angle of B is $\angle B=19^{\circ}$