Question

5 Mario places a laptop on a desk. He adjusted the screen so that the screen is at an angle of 81° with the desk. What is the measure of the unknown angle? Explain.

Answer 1

Mario places a laptop on a desk. He adjusted the screen so that the screen is at an angle of 81° with the desk.

We are asked to find the measure of the unknown angle x

Recall the straight-angle property,

The sum of angle x and angle 81° must be equal to 180°

So, we can write

`x+81\degree=180\degree`

Let us solve the above equation for the unknown angle x

`\begin{gathered} x+81\degree=180\degree \\ x=180\degree-81\degree \\ x=99\degree \end{gathered}`

Therefore, the unknown angle x is 99°