This is a regular heptagon (7-sided figure )
It will be composed of 7 congruent isosceles triangles.....
Their equal sides will be 5 and the included angle between these sides = (360 / 7)°
The area is given by
7 ( 1/2) 5^2 * sin (360 / 7)° ≈ 68.4 units^2
help.
