The formula of calculating an interior angle

The formula for calculating an interior angle of a polygon is given by:

$$\text{Interior Angle} = \frac{(n-2) \times 180^\circ}{n}$$

where $n$ is the number of sides of the polygon.

For example, for a triangle ($n = 3$):

$$\text{Interior Angle} = \frac{(3-2) \times 180^\circ}{3} = \frac{180^\circ}{3} = 60^\circ$$

For a square ($n = 4$):

$$\text{Interior Angle} = \frac{(4-2) \times 180^\circ}{4} = \frac{360^\circ}{4} = 90^\circ$$