How many diagonals does a polygon with 15 sides have?
Note
A diagonal joins two non-adjacent vertices. Use n(n − 3) ÷ 2; for 15 sides, that gives 90 diagonals.
How many diagonals does a polygon with 15 sides have?
A diagonal joins two non-adjacent vertices. Use n(n − 3) ÷ 2; for 15 sides, that gives 90 diagonals.