A 7 sided heptagon can be divided into 5 triangles
Yes, it can always be divided in 2 triangles. This is because every quadrilateral has 2 diagonals. It is these diagonals that divide the quadrilateral into 2 triangles.
If you are merely drawing from one vertex to all the others, the number of triangles in any n-sided figure is equal to n-2. In this case, a heptagon has seven sides, and thus (7 - 2) = 5 triangles can be drawn.
A hexagon (six-sided polygon) can be divided into 4 triangles by drawing all of the diagonals from one vertex (only three lines can be drawn in this case, since each vertex already connects to two others on the edges of the form). If you instead drew lines from the center to each vertex, you would get 6 triangles.
Probably 6 if not 4 if not 8 if not 10.WHO CARES
A regular hexagon can be divided into 6 equilateral triangles by drawing diagonals between opposite vertices, if that helps.
Number of sides minus 2 equals the number of triangles within the polygon.