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