Answer
x=135, y=45
Work Step by Step
The angle marked $x$ and the angle marked $3y$ form a corresponding angle pair. The corresponding angle theorem tells us they are congruent.
$x=3y\longrightarrow$ definition of congruent
The angle marked $x$ and the angle marked $y$ form a linear pair, so they are supplementary.
$x+y=180\longrightarrow$ definition of supplementary
$3y+y=180\longrightarrow$ substitution
$4y=180\longrightarrow$ combine like terms
$y=45\longrightarrow$ division property of equality
Substitute in the first equation to find the value of x.
$x=3y=3(45)=135$
