Nos of sides of a regular polygon is given by: \(\frac{(n - 2) \times 180}{\text{n}}\) = One interior angle of the polygon. where n = number of sides of the polygon 168 = \(\frac{(n - 2) \times 180}{\text{n}}\) Cross multiplying, we have: 168n = 180n - 360 168n - 180n = - 360 - 12n = - 360 n = \(\frac{-360}{-12}\) = 30.