A diagonal of a polygon is an segment between two non-adjacent vertices of the polygon. How many diagonals does a regular 10-sided polygon have?  Select the correct option:  A) 875  B) 35  C) 1425  D) 2025  E) 2500
There's a direct formula for this.   Number of diagonals in a regular polygon = [n*(n-3)] / 2, n = number of sides of the regular polygon.   Here, n = 10.   Plugging it in, we get 35 diagonals!   Answer (35).
<result>B</result>
A diagonal of a polygon is an segment between two non-adjacent vertices of the polygon. How many diagonals does a regular 10-sided polygon have?