Alright, so i have a question that says this:
a regular octagon has sides mesuring about 4 cm. if the octagon is divided into 8 congruent triangles, each has a height of 5 cm. what is the area of the octagon?
i don't know if i divide my answer in half, like so:
5x4=20
do i divide my answer in half now or go on to multiply 20 by 8?

Octogon
sides=4
draw lines from the outside angles to the center so they form 8 equal triangle sections
find the area of each triangle and multiply by 8

area of triangle=1/2 base times height
base=4
the height is the distance from the center of one side of the octogon, to the center=5
so area=4 times 1/2 times 5=4 times 5=10

8 triangles so 8 times 10=80
the answer is 80cm^2
the diagram included below shows area for a pentagon

5(2a-5+b). xbox xboxxbx xb