Question

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A carpenter is building a roof on a barn that is w feet wide and ℓ feet long. The roof will be covered by corrugated tin and the carpenter needs to know the area of the roof to estimate the amount of tin to purchase. The roof will have a pitch of 4:12. Find an expression for the area of the roof in terms of w and ℓ feet long. Note: the pitch of a roof is ratio of the rise to the run as in the picture below

Answer 1

CAN I PLEASE GET SOME HELP ON HOW TO DO THIS NOT LOOKING FOR THE ANSWER JUST NEED A HEAD START ON HOW... ANYONE, THANK YOU!

Answer 2

Do you know the formula for calculating area of a triangle?

Answer 3

that would be the place to start :)

Answer 4

@mlb8482 are you there?

Answer 5

yes sorry

Answer 6

multiply the base by the height, and then divide by 2

Answer 7

yup exactly, now you have the base and the height given to you in the ratio: 4: 12 , which is the rise over the run. Can you work out what the area of the triangle is?

Answer 8

on min... brb going to try to figure it out...

Answer 9

cool, good luck :)

Answer 10

okay so i am lost

Answer 11

okay no problem, I will explain. You know that the area of a triangle is base * height / 2, right?
OK, so in the picture there is a triangle with rise going up, and run going across.
type 'yes' if your following me so far, and I will continue :)

Answer 12

yes

Answer 13

great! OK, so the other thing we know is the ratio for that triangle's rise(height) over the run(base), which is 4:12, or height 4: run 12.

Now you can work out the area of the triangle because our formula of base * height / 2 will turn into 12 * 4 / 2. Can you work that out?

Answer 14

the height = 4 and the base = 12

Answer 15

let me see hold on please

Answer 16

OK

Answer 17

okay i got 24 wrong huh but i just need an expression
I am lost

Answer 18

24 is right! the expression is coming, now the expression ((( 24 * length ))) is the answer. That expression will give you the total area of the roof. Try to imagine it, you have worked out the area of the triangle and then you have to times it by the length of the roof.

24 * length

Understand?

Answer 19

yes hold on

Answer 20

okay so my final answer is 24*L because all i need is to find the expression... or am i just not getting it

Answer 21

Yes, you got it! Well done! that's the answer. It's important to know why it's the answer too for next time you won't get stuck.

Answer 22

yes and thank you SO MUCH!!!

Answer 23

your welcome :)