How many diagonals does a polygon with 9 sides have?
Note
A diagonal joins two non-adjacent vertices. Use n(n − 3) ÷ 2; for 9 sides, that gives 27 diagonals.
How many diagonals does a polygon with 9 sides have?
A diagonal joins two non-adjacent vertices. Use n(n − 3) ÷ 2; for 9 sides, that gives 27 diagonals.