Question

Find an angle which is 10° less than four times its supplement?

Answer 1

From the question, we're asked to find an angle that is 10degrees less than 4 times its supplement;

Let's denote the angle as y;

Remember, that supplementary angles are angles that add up to 180degrees. Therefore, to find the supplement of the required angle, we'll have,

$180-y=\text{ the supplement of the required angle}$

We've been also told that the said angle is 10degrees less than 4times its supplement which we can express mathematically as per below and solve for ;

$\begin{gathered} 180-y=4y-10 \\ 5y=190 \\ y=38^{\circ} \end{gathered}$

Therefore, the required angle is 38degrees.

$\text{Its supplement = 180-y = 180-38 =}142^{\circ}$