seven
Improved Answer:-
14 diagonals
A heptagon has 4 diagonal lines and 7 sides and it has 2 congruent diagonal lines and 2 congruent triangles
it has 4 :)
14
14.
A heptagon can have 0, 1 or 7 lines of symmetry. 7 only if it is a regular heptagon.
A 7 sided heptagon has 14 diagonals
A heptagon can have all 7 lines that are perpendicular to one or both its neighbours.
A heptagon s bounded by seven straight sides.
A heptagon contains zero parallel lines. All of the lines in a regular heptagon with all sides and angles equal are at different angles from each other.
An irregular 7 sided heptagon normally has no lines of symmetry depending how it is constructed.
Seven.
It has 7 lines of symmetry