❖ In this lesson, we explain why two exterior angles at a vertex are equal (Proof) and why they are equal.

Using clear visuals and a step-by-step explanation, you’ll see how these two angles are actually opposite (vertical) angles, formed when you extend different sides of a triangle at the same vertex.

You’ll also understand why it doesn’t matter which one you choose when calculating the sum of exterior angles.

🎯 Key concepts covered:

✔ Why a vertex can show two exterior angles

✔ What are opposite (vertical) angles?

✔ Why vertical angles are equal in measure

✔ Why we only count one exterior angle per vertex in the \(360^\circ\) sum

✅ This lesson helps clarify a small but important detail when learning about exterior angles of triangles and polygons.