Question

What is the measure of one angle in a regular 25-gon?

Answer 1

The sum of the interior angles in an n-gon is
∑angles = 180(n-2)

Since we have a regular 25-gon, all of the angles will be equal in measure.

So, each angle will be: m∠X=180(n-2)/n = 180 x 23/25 = 165.6  deg