Question

linear pairs and vertical angles
in which diagram are angles 1 and 2 vertical angles?

Explanation:

Step1: Recall the definition of vertical angles

Vertical angles are the angles opposite each other when two lines cross.

Step2: Analyze each diagram

• In the first diagram, angles \(1\) and \(2\) are adjacent and form a linear pair (sum to \(180^{\circ}\)), not vertical angles.
• In the second diagram, angles \(1\) and \(2\) are adjacent and form a right - angled situation (sum to \(90^{\circ}\)), not vertical angles.
• In the third diagram, angles \(1\) and \(2\) are opposite each other when two lines cross, so they are vertical angles.

Answer:

The third diagram.