62. A roof in the e
escape through it
side BC is 9.8 m, and
in the shape of a rectangular pyramid is going to be filled with insulation so that heat does not
through it. The dimensions of the attic are shown in the following diagram. Side AB is
BC is 9.8 m, and side EC is 12.9 m. Answer the following questions to determine the heign
the attic. Round your answers to one decimal place.
s to determine the height, EF of
12.9 m
9.8 m
14.6 m
a) To find the height of EF using the Pythagorean Theorem, you first have to find the distance
(Hint: start by determining the length of AC, then you can figure out the length of Ch)
CF=
b) Determine the length of EF.

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figaroperfect figaroperfect · Answer 1 · 2019-12-01T22:36:21+01:00

Answer:

9.4m

Step-by-step explanation:

Let the diagram of the rectangular pyramid be as shown in the attached

If a point C' is selected midway between C and B and F' is selected midway between D and C as shown in pyramid 2

FC can then be computed using pythagoras theorem such that

FC^2 = FC'^2 + CC'^2

FC^2 = (14.6/2)^2 + (9.8/2)^2

FC^2 =53.29 + 24.01

FC^2 = 77.3

FC = sqrt(77.3) = 8.8

To determine the height of the attic, we estimate EF, Pythagoras theorem can be used for triangle EFC

such that EC^2 = EF^2 + FC^2

therefore EF^2 = EC^2 - FC^2

EF^2 = 12.9^2 - 8.8^2

EF^2 = 166.41 - 77.44

EF^2 = 88.97

EF = sqrt(88.97)

EF = 9.4

The height of the attic is therefore 9.4m