None unless (for example) you draw lines from each corner to the center, and then you'll have five. But there's an infinite number of ways of drawing isosceles triangles in a pentagon. (Choose any part of one edge, and use that as the base of your triangle, and then choose a height).
There are 3 triangles in a pentagon
The base is a pentagon. It has five isosceles triangles rising from the sides to a point above it.
3 triangles
5
Isosceles triangles can be used in domes
There are 3 triangles in a pentagon
It can be, if all the vertices of the pentagon are joined to its centre. But if they are joined to any other point, it will not be.
A pentagon has 3 triangles and 5 sides
All isosceles triangles are not equilateral triangles
All isosceles triangles are not equilateral triangles
The base is a pentagon. It has five isosceles triangles rising from the sides to a point above it.
3 triangles
20.
Three
three
5
Isosceles triangles can be used in domes