SOLUTION: Word Problem: The insulation comes in 40cm wide rolls that are cut to fit between the rafters in the attic. The roof is 7m from peak to eave and the attic space is 3m high at the

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Question 118406: Word Problem: The insulation comes in 40cm wide rolls that are cut to fit between the rafters in the attic. The roof is 7m from peak to eave and the attic space is 3m high at the peak, how long does each piece of insulation need to be? Round to the nearest tenth.
40^2=7^2+3^2
Am I using the right formula in order to solve this problem?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
The insulation comes in 40cm wide rolls that are cut to fit between the rafters in the attic. The roof is 7m from peak to eave and the attic space is 3m high at the peak, how long does each piece of insulation need to be? Round to the nearest tenth.
:
you sort of have the right idea, however:
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The width of the insulation (40 cm) has no bearing on the problem
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The roof consists of two right triangles, back-to-back /|\.
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We want to find the base of one of the triangles then double it
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The height is given as 3 m "|"; call it b
The hypotenuse is given as 7 m; "/" or "\"; call it c
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Find the base (a) using the pythagorean theorem: a^2 + b^2 = c^2
a^2 + 3^2 = 7^2
a^2 + 9 = 49
a^2 = 40 - 9
a^2 = 40
a = sqrt%2840%29
a = 6.32455
double this:
12.6 meters is the length of the insulation
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