## anonymous 5 years ago Find the volume of a regular pentagonal prism with a 7in apothem, 12 inch side length and a 30in length, im really stuck on this so help would be awesome!<3

1. anonymous

here's a pic if it helps:)

2. anonymous

Volume of Prism = (5/2)ash = Ah where, a = apothem length, s = side, h = height, A=area

3. anonymous

oky so (5/2)ash should equal the area multiplied by the height?

4. anonymous

yup${5\over2}\times (apothem) \times side \times height = Area \times Height$

5. anonymous

with side do you mean side length or the number of sides?

6. anonymous

annd would height be the diameter?

7. anonymous

7in apothem 30in length (if yu turn the prim up-side the length turns into height, right?) 12 inch side length = side

8. anonymous

oh okay so the length would be the height. annd why is it 5/2 at the beginning is that some sort of equation?

9. anonymous

hmm.. it's from deriving the equation... it's just like the area for a triagle = (1/2)bh

10. anonymous

oh is there an equation for a pentagonal prism?

11. anonymous

oh and in the equation you said it will = area* height, did you mean the area of the pentagon?

12. anonymous

OH! never mind i just didnt read ur answer right I get how you got 5/2 xD and this makes perfect sense now so thanks so much you're really smart!!

13. anonymous

haha thank's (:

14. anonymous

hey could you help me on a problem? i have it posted but i cant seem to get any responses. thanks<33

15. anonymous

sorry i was eating, i'll look for yur post and try to help

16. anonymous

Thanks so much C: and its the one with a triangular prism on top and a rectangular prism on bottom.

17. anonymous

you should re-post the question, i can't find it hehe

18. anonymous

haha okay I will thanks so much again:)

19. anonymous

did you find it? :)

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