Three or more - up to infinitely many.
Any number that is greater than or equal to 3.
The only general way is to divide the pentagon into three triangles, calculate the areas of the triangles and add them together.
6-2 = 4 triangles
Three triangles
5
draw it out it helps
3 triangles
five
It can be divided into 18, hope this helps!
A 7 sided heptagon can be divided into 5 triangles
5 triangles.
98