Here is a hexagon using 6 matchsticks. Move 4 matchsticks to create 2 triangles.
Here we have 2 triangles, with the small one inside the large one. Can you move 3 matchsticks to have 4 triangles?
Arrange the 6 matchsticks to form 4 equilateral triangles with an edge length equal to that of a single matchstick. Hint: you are allowed to use glue.
Move 4 matchsticks to create 5 triangles, the triangles don't have to be equal in size.