A diagonal of a polygon is an segment between two non-adjacent vertices of the polygon. How many diagonals does a regular 45-sided polygon have?	Pick one.
A) 875 B) 945 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 = 45.   Plugging it in, we get 945 diagonals!   Answer (945).
<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 45-sided polygon have?