If the external angle of a regular polygon is 18°, then the number of diagonals in this
polygon is
Show answer & explanation
Correct answer: C
Explanation
The correct answer is Option 3 i.e. 170
Given that
The external angle of a polygon = 18º
The number of sides of the polygon = 360º/18º = 20
The number of the diagonal of the polygon = 20 * (20-3)/2 = 170