Question

Find side x , give your answer 1 decimal place ​

Answer 1

Given:

Let A denote the angle of the given triangle which measures ∠A = 81°

Let B denote the angle which measures ∠B = 40°

The length of the side a = x.

The length of the side b = 7 cm.

We need to determine the value of x.

Value of x:

The value of x can be determined using the law of sine formula.

Applying the law of sine, we have;

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

Substituting the values, we have;

$\frac{sin \ 81^{\circ}}{x}=\frac{sin \ 40^{\circ}}{7}$

Simplifying, we get;

$\frac{0.988}{x}=\frac{0.643}{7}$

Cross multiplying, we have;

$0.988 \times 7=0.643 x$

     $6.916=0.643x$

       $10.8=x$

Thus, the length of the side x is 10.8 cm.