Question

Find the length of side BC. Give your answer to 3 significant figures

Answer 1

Answer:

$\huge\boxed{\sf BC = 19.4 \ cm}$

Step-by-step explanation:

Given:

θ = 71°

Adjacent = AB = 6.3 cm

Required:

Hypotenuse = BC = ?

We will use the trigonometric ratio of cos.

$\displaystyle cos \theta = \frac{Adjacent}{Hypotenuse} \\\\cos \ 71 = \frac{6.3}{BC} \\\\0.33 = \frac{6.3}{BC} \\\\BC =\frac{6.3}{0.33} \\\\\boxed{BC = 19.4 \ cm}\\\\\rule[225]{225}{2}$