how many triangles can you make by joining the diagonals of a pentagon?

To determine how many triangles you can make by joining the diagonals of a pentagon, you need to understand the general formula for finding the number of triangles in an n-sided polygon.

The formula for calculating the number of triangles in an n-sided polygon is:
Number of triangles = (n - 2) * (n - 3) / 2

In the case of a pentagon (which has 5 sides), we can substitute n = 5 into the formula and calculate as follows:

Number of triangles = (5 - 2) * (5 - 3) / 2
= 3 * 2 / 2
= 6 / 2
= 3

Therefore, by joining the diagonals of a pentagon, you can make a total of three triangles.