Question

20уX120°y = [ ? jºEnter

Answer 1

Determine the measure of angle x by using angle sum of triangle.

$\begin{gathered} x+20+120=180 \\ x=180-140 \\ =40 \end{gathered}$

The angle x and angle y forms a linear pair of angles. So,

$x+y=180$

Substitute 40 for x in the equation to determine the measure of angle y.

$\begin{gathered} 40+y=180 \\ y=180-40 \\ =140 \end{gathered}$

So measure of angle y is,

y = 140 degrees.