📚 Vertical Angles Theorem

When two lines intersect, vertical angles are always equal.

Vertical angles are the angles opposite each other when two lines cross. In the diagram below, angles 1 & 3 are vertical angles, and angles 2 & 4 are vertical angles.

💡 Key Points to Remember

• Vertical angles are always equal (∠1 = ∠3 and ∠2 = ∠4)
• Adjacent angles are supplementary (they add up to 180°)
• All four angles together equal 360°