Quantcast

Got Homework?

Connect with other students for help. It's a free community.

  • across
    MIT Grad Student
    Online now
  • laura*
    Helped 1,000 students
    Online now
  • Hero
    College Math Guru
    Online now

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

cbrusoe Group Title

Megan bought an outdoor wall light fixture. The fixture has semicircular ends at the top and bottom as shown. The side of the fixture that faces the wall is open. What is the exterior surface area of the light fixture? Answer 78π in2 84π in2 108π in2 120π in2

  • 2 years ago
  • 2 years ago

  • This Question is Closed
  1. cbrusoe Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    • 2 years ago
  2. apoorvk Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    Just need to find the surface area of each semicircle part, and add 'em up. Or rather, two same semicircles make a circle! so, find out the are of a circle which has a diameter of '12in'. Then, add the area of the rectangular part --> 12x14 - right? What do you think now?

    • 2 years ago
  3. cbrusoe Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    i did something way off ... but im not sure what i found the formula for a cylinder and i plugged in my numbers and calculated it and got 753.6 ....

    • 2 years ago
  4. apoorvk Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    it's not a cylinder! its like a lampshade kinda thing - two semicircular shades, and a rectangular background.

    • 2 years ago
  5. cbrusoe Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    i know but if we added the other half... aha ... ok so what equation do i use?

    • 2 years ago
  6. apoorvk Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    find the area of the rectangular part, then are of each semi-circular shade and add em up!

    • 2 years ago
  7. cbrusoe Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    ok the area of the rectangular part is 168 now i need to find the area of each semi-circular shade ... how do i do that?

    • 2 years ago
  8. cbrusoe Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    sorry ive been working since 6 this morning non-stop... i dont think im trying as hard ... cuz this probably something i should get

    • 2 years ago
  9. apoorvk Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    its okay - i am woozy too :P. area of semi-circle = (1/2) area of circle plus you could think this way - two same semicircles make a circle, so just find the area of the the equivalent circle..

    • 2 years ago
  10. cbrusoe Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    ok well i know the formula for the area of a circle is pi*r2 so since the diamiter is 12 the radius would be 6 plug that in and i got 113.04

    • 2 years ago
  11. cbrusoe Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    uugh but adding those up gives me to big of a number hmmm

    • 2 years ago
  12. apoorvk Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    113 + 168 isn't right?

    • 2 years ago
  13. cbrusoe Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    well it adds up to 281 which isnt one of my options

    • 2 years ago
  14. apoorvk Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    what are your options?

    • 2 years ago
  15. cbrusoe Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    78π in2 84π in2 108π in2 120π in2

    • 2 years ago
  16. apoorvk Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    i am sorry, it's too late here, and i am too woozy - i misunderstood the whole thing - it must be a cylinder itself - i am really sure this time though. @Diyadiya will help you out. Thanks :) and apologies for misguiding - didn't mean it.

    • 2 years ago
  17. Diyadiya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    I got one answer :D

    • 2 years ago
  18. cbrusoe Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    it's ok thanks for the help =) and ok =)

    • 2 years ago
  19. apoorvk Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    yeah would be -the last one - just help her understand.

    • 2 years ago
  20. Diyadiya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    First find the area of two semicircles area of semicircle = (pi * r^2)/2 =pi*(6)^2/2 =18pi 2 semicircles =18pi+18pi=36pi

    • 2 years ago
  21. Diyadiya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    did you understand til this ?

    • 2 years ago
  22. cbrusoe Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    yeahh when we go to the semi circle stuff i think is when i started to get confused

    • 2 years ago
  23. Diyadiya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    Now its half of a cylinder

    • 2 years ago
  24. Diyadiya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    and i guess the rectangular part is open

    • 2 years ago
  25. Diyadiya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    You just have to find the lateral surface area of half of cylinder ( 2*pi*r*h) half cylinder so lateral surface area = 2*pi*r*h/2 =Pi*r*h can you do it?

    • 2 years ago
  26. Diyadiya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    @cbrusoe ??

    • 2 years ago
  27. cbrusoe Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    yeahh i can do it thank-you =)

    • 2 years ago
  28. Diyadiya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    can you tell me the lateral surface area of it ?

    • 2 years ago
  29. Diyadiya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    take your time np

    • 2 years ago
  30. cbrusoe Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    ok when i calculate 2*pi*r*h i got 263.76

    • 2 years ago
  31. Diyadiya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    don't take the value of pi .. just keep pi like that since your answer contains pi

    • 2 years ago
  32. Diyadiya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    so what will be the lateral surface area ?

    • 2 years ago
  33. cbrusoe Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    ok so 2*r*h and my diamiter is 12 so radius would be 6 and height is 14 so 2*6*14 = 168pi?

    • 2 years ago
  34. Diyadiya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    Yes this is the lateral surface area of a cylinder but we have only half of a cylinder so divide it by 2

    • 2 years ago
  35. Diyadiya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    and add the area of 2 semicircles

    • 2 years ago
  36. cbrusoe Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    ok so 84 plus the are of 2 semicircles

    • 2 years ago
  37. Diyadiya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    Yes

    • 2 years ago
  38. Diyadiya Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    so what is it ?

    • 2 years ago
  39. cbrusoe Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    120

    • 2 years ago
  40. cbrusoe Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    i may have calcuulated that last part wrong

    • 2 years ago
    • Attachments:

See more questions >>>

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.