Exterior angles of polygons

key notes :

🔹 What is an Exterior Angle?

• An exterior angle of a polygon is formed when a side of a polygon is extended outward.
• It is the angle between the extended side and the next side of the polygon. 🔻➖

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🔄 Exterior Angle & Interior Angle Relationship

• Exterior angle + Interior angle = 180° (they form a linear pair) ➕📐
  Example: If interior angle is 120°, exterior angle = 180° – 120° = 60°.

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🧮 Sum of Exterior Angles

• For any polygon (regular or irregular):
  ✅ Sum of all exterior angles = 360°
  Example: Triangle, square, pentagon… always 360° 🎉

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📏 Exterior Angle of a Regular Polygon

A regular polygon has all sides and angles equal.

Formula:

Exterior Angle = 360° / Number of sides​

Examples:

Polygon	Sides	Each Exterior Angle
Triangle 🔺	3	360° ÷ 3 = 120°
Square ⬜	4	360° ÷ 4 = 90°
Pentagon 🔷	5	360° ÷ 5 = 72°
Hexagon 🔶	6	360° ÷ 6 = 60°

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🧠 How Many Exterior Angles?

• Every polygon has the same number of exterior angles as its sides.
  Example: Hexagon = 6 sides → 6 exterior angles ✅

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🗝️ Key Tips to Remember

✨ Exterior angle = turning angle when you walk around a polygon.
✨ If you go around a polygon once, you make a full turn = 360° 🔄
✨ Regular polygon exterior angles are equal.

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🔍 Quick Practice

1️⃣ A regular octagon has 8 sides. Each exterior angle = 360° ÷ 8 = 45°
2️⃣ If an exterior angle of a regular polygon is 30°, number of sides = 360° ÷ 30° = 12 sides

Learn with an example

let’s practice! 🖊️