Try this ACT math practice question on finding the relationship between the angles formed by a line intersecting a pair of parallel lines.

In the figure below, $l \parallel m$ and $m \perp n$. What is $y$ in terms of $x$ ?

- $\quad x-45$
- $\quad x-90$
- $\quad 45-x$
- $\quad 90-x$
- $\quad 180-x$

**Video explanation**