It has 7 sides
A 7 sided heptagon contains 5 triangles.
A heptagon Heptagon.
A heptagon has seven sides.
A heptagon is a polygon with 7 sides.
In a regular heptagon, there are 7 lines of symmetry because there is one line of symmetry for every side.
A heptagon has seven sides, so a regular heptagon has seven lines of symmetry (they run from each vertex to the middle of the opposite side).
7, 9 and 10 respectively