Question

Find the total area for the prism

Answer 1

I'm assuming that's a regular pentagon. Do you know how to find out it's area?

Answer 2

not really

Answer 3

Okay. You're given k, and that each side is 20". So divide your pentagon into 5 triangles, from each point.
Like this:
http://www.math-prof.com/geom/Ch_26_Fig_04.jpg
Can you solve it now?

Answer 4

okay! so the formula they gave me was TA(total area)=ph (perimeter times height)
+ 2b (b=base) so would it be TA=20 times 6 + 2(6)?

Answer 5

I don't think so. I would start by taking one side of the pentagon, i.e. 20/5 = 4. Then multiply that by the apothem (the line from the center to the side), k, to get 4k, then divide that by two to get the area of one triangle. Then multiply by 5, to get 10k. Do you understand?

Answer 6

Yes. yes. yes. yes

Answer 7

Oh, i misunderstood, yes you're right, TA = ph + 2base. So, we now know that base = 10k. Can you calculate TA?