Question

Please help with this right triangle problem

Answer 1

Given:

The figure of a right angle triangle.

To find:

The measure of side AB.

Solution:

In a right angle triangle,

$\cos \theta=\dfrac{Adjacent}{Hypotenuse}$

In the given triangle,

$\cos B=\dfrac{BC}{AB}$

$\cos (20^\circ)=\dfrac{7}{AB}$

$\cos (20^\circ)AB=7$

$AB=\dfrac{7}{\cos (20^\circ)}$

On further simplification, we get

$AB=\dfrac{7}{0.93969}$

$AB=7.449265$

$AB\approx 7.45$

Therefore, the measure of AB is 7.45 units.