# algebra

posted by
**KB** on
.

A homeowner wishes to insulate her attic with fiberglass insulation to

conserve energy. The insulation comes in 40-cm wide rolls that are cut to fit between the rafters in the attic. If the roof is 6 m from peak to eave and the attic space is 2 m high at the peak, how long does each of the pieces of insulation need to be?

Round to the nearest tenth.

if the roof of the house is 7 m from peak to eave and the attic space is 3 m high at the peak, how long does each of the pieces of insulation need to be? Round to the nearest tenth.

I think you use the Pythagorean theorem. I got:

7sq = 3sq + b sq

49 = 9 + b sq

49-9=40

b = 40

after this I'm lost. what is the sq rt of 40? do I need to multiply this by 2?

pls help!!

Put this in the Google search window:

sqrt(40)

(Google has a nice calculator built in. No, don't multipy it by 2. You only do ones side at a time.

so, I got sqrt40 = 6.32

does that mean that each piece of insulation needs to be 6.32 m ?

yes, that is the length of the piece from the eave to the ridge.

yes, that is the length of the piece from the eave to the ridge.