If in a regular polygon the number of diagonals is 54, then the number of sides of this po…

Question

If in a regular polygon the number of diagonals is 54, then the number of sides of this polygon is:

Accepted Answer

$$\frac{n(n-3)}{2} = 54 \implies n^2-3n-108=0 \implies (n-12)(n+9)=0 \implies n=12$$

Solutions · 1