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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
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

apoorvk Group TitleBest ResponseYou've already chosen the best response.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

cbrusoe Group TitleBest ResponseYou've already chosen the best response.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

apoorvk Group TitleBest ResponseYou've already chosen the best response.2
it's not a cylinder! its like a lampshade kinda thing  two semicircular shades, and a rectangular background.
 2 years ago

cbrusoe Group TitleBest ResponseYou've already chosen the best response.1
i know but if we added the other half... aha ... ok so what equation do i use?
 2 years ago

apoorvk Group TitleBest ResponseYou've already chosen the best response.2
find the area of the rectangular part, then are of each semicircular shade and add em up!
 2 years ago

cbrusoe Group TitleBest ResponseYou've already chosen the best response.1
ok the area of the rectangular part is 168 now i need to find the area of each semicircular shade ... how do i do that?
 2 years ago

cbrusoe Group TitleBest ResponseYou've already chosen the best response.1
sorry ive been working since 6 this morning nonstop... i dont think im trying as hard ... cuz this probably something i should get
 2 years ago

apoorvk Group TitleBest ResponseYou've already chosen the best response.2
its okay  i am woozy too :P. area of semicircle = (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

cbrusoe Group TitleBest ResponseYou've already chosen the best response.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

cbrusoe Group TitleBest ResponseYou've already chosen the best response.1
uugh but adding those up gives me to big of a number hmmm
 2 years ago

apoorvk Group TitleBest ResponseYou've already chosen the best response.2
113 + 168 isn't right?
 2 years ago

cbrusoe Group TitleBest ResponseYou've already chosen the best response.1
well it adds up to 281 which isnt one of my options
 2 years ago

apoorvk Group TitleBest ResponseYou've already chosen the best response.2
what are your options?
 2 years ago

cbrusoe Group TitleBest ResponseYou've already chosen the best response.1
78π in2 84π in2 108π in2 120π in2
 2 years ago

apoorvk Group TitleBest ResponseYou've already chosen the best response.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

Diyadiya Group TitleBest ResponseYou've already chosen the best response.3
I got one answer :D
 2 years ago

cbrusoe Group TitleBest ResponseYou've already chosen the best response.1
it's ok thanks for the help =) and ok =)
 2 years ago

apoorvk Group TitleBest ResponseYou've already chosen the best response.2
yeah would be the last one  just help her understand.
 2 years ago

Diyadiya Group TitleBest ResponseYou've already chosen the best response.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

Diyadiya Group TitleBest ResponseYou've already chosen the best response.3
did you understand til this ?
 2 years ago

cbrusoe Group TitleBest ResponseYou've already chosen the best response.1
yeahh when we go to the semi circle stuff i think is when i started to get confused
 2 years ago

Diyadiya Group TitleBest ResponseYou've already chosen the best response.3
Now its half of a cylinder
 2 years ago

Diyadiya Group TitleBest ResponseYou've already chosen the best response.3
and i guess the rectangular part is open
 2 years ago

Diyadiya Group TitleBest ResponseYou've already chosen the best response.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

Diyadiya Group TitleBest ResponseYou've already chosen the best response.3
@cbrusoe ??
 2 years ago

cbrusoe Group TitleBest ResponseYou've already chosen the best response.1
yeahh i can do it thankyou =)
 2 years ago

Diyadiya Group TitleBest ResponseYou've already chosen the best response.3
can you tell me the lateral surface area of it ?
 2 years ago

Diyadiya Group TitleBest ResponseYou've already chosen the best response.3
take your time np
 2 years ago

cbrusoe Group TitleBest ResponseYou've already chosen the best response.1
ok when i calculate 2*pi*r*h i got 263.76
 2 years ago

Diyadiya Group TitleBest ResponseYou've already chosen the best response.3
don't take the value of pi .. just keep pi like that since your answer contains pi
 2 years ago

Diyadiya Group TitleBest ResponseYou've already chosen the best response.3
so what will be the lateral surface area ?
 2 years ago

cbrusoe Group TitleBest ResponseYou've already chosen the best response.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

Diyadiya Group TitleBest ResponseYou've already chosen the best response.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

Diyadiya Group TitleBest ResponseYou've already chosen the best response.3
and add the area of 2 semicircles
 2 years ago

cbrusoe Group TitleBest ResponseYou've already chosen the best response.1
ok so 84 plus the are of 2 semicircles
 2 years ago

Diyadiya Group TitleBest ResponseYou've already chosen the best response.3
so what is it ?
 2 years ago

cbrusoe Group TitleBest ResponseYou've already chosen the best response.1
i may have calcuulated that last part wrong
 2 years ago
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