Question

there is a diagram with two horizontal parallel lines and a transversal. the angle between the upper horizontal line and the transversal is 109°, and we need to find the measure of angle x° between the lower horizontal line and the transversal.

Explanation:

Step1: Identify vertical angles

Vertical angles are equal. The angle opposite to $x^\circ$ is vertical to $x^\circ$.

Step2: Find supplementary angle

The $109^\circ$ angle and its adjacent angle (vertical to $x^\circ$) are supplementary. So adjacent angle = $180^\circ - 109^\circ = 71^\circ$.

Step3: Determine x

Since vertical angles are equal, $x = 71$.

Answer:

71