1. Tardigrade
  2. Question
  3. Mathematics
  4. The number of diagonals that can be drawn by joining the vertices of an octagon, is

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. The number of diagonals that can be drawn by joining the vertices of an octagon, is

J & K CETJ & K CET 2003

Solution:

By joining any two points of a vertices, we get a diagonal, but we have to subtract the sides of a octagon.
$ \therefore $ Number of diagonals $ {{=}^{8}}{{C}_{2}}-8 $
$=\frac{8\times 7}{2\times 1}-8=20 $