Exterior/Interior Angles

For a regular n-gon, there are simple formulas to find its angles:

• Sum of Exterior Angles: Always 360°.
• Each Exterior Angle: $\frac{360°}{n}$.
• Each Interior Angle: $180° - \text{Exterior Angle} = 180° - \frac{360°}{n} = \frac{180(n-2)}{n}$.
• Sum of Interior Angles: $n \times \text{Interior Angle} = 180(n-2)$.

Also remember:

• Complement of an angle θ: 90° - θ
• Supplement of an angle θ: 180° - θ