Angles & Parallel Lines Worksheet

Sample problems

Use angle facts to find each unknown. When two parallel lines are cut by a transversal: corresponding angles are equal, alternate interior angles are equal, and same-side interior angles add to $180^{\circ }$. In any triangle the three angles add to $180^{\circ }$, and an exterior angle equals the sum of the two remote interior angles.

1. 1. Lines $m$ and $n$ are parallel. Find the value of $x$.
2. 2. Two straight lines cross. One of the four angles is $110^{\circ }$. Find $x$, the measure of the angle directly opposite it (its vertical angle).
3. 3. Lines $m$ and $n$ are parallel. Find the value of $x$.
4. 4. Lines $m$ and $n$ are parallel. Find the value of $x$.

Plus 10 more problems and a full answer key in the PDF.