**house**.

The question was :

The surface area of walls, roofs, doors, and windows all affect the amount of heat loss from a house. Calculate the surface area for the

**doors,windows, walls, and roof**for the house below. Express each answer to the**nearest tenth****o****f a square metre.**

wi

ndo

ws = 80cm x 60cm each

doors = 205cm x 82

cm each

-back of the house is identical to the front

-sides of the house are identical to each other

I started off with the windows. Since there are 3 window in the front and 2 window on the side, and the opposite sides are equal there would be 10 windows all together [(3+2)(2)]

Here is how I got the area of the windows:

First, I converted the centimetres into metres by dividing it by 100

80/100= 0.8m

60/100= 0.6m

**SA = 10(lw)**

**= 10(0.8 x 0.6)**

**= 10 (0.48)**

**= 4.8 squared m**

Now, I will calculate the area of the doors. Since, the back and front of the house are both identical, there would be 2 doors :

I also had to convert the cm in m:

**SA = 2 (lw)**

**= 2 (2.05 x 0.82)**

**= 2 ( 1.68)**

**= 3.36 squared m**

For me, finding the area of the walls got a little tricky. What I did was find the sides of the walls, then subtracted the area of the doors and windows:

**SA = 2 (lw) = 2 (lw)**

**= 2 ( 4.8 x 2.5) + (2.5 x 7)**

**= 2 (12) + 2 (17.5)**

**= 24 + 35**

**= 59 squared m**

- after adding everything, together, I had to subtract the area taken up by the windows and doors.

-the area of the doors was 3.36 squared m

- but for the windows, only 8 are on the walls so I had to find the surface area of 8 windows:

SA = 8 (0.8 x 0.6)

= 8 (0.48)

= 3.84 squared m

**SA = 59 - 3.36 - 3.84**

**= 51.8 squared m**

Lastly, I have to find the area of the roof I did that using two different steps, the rectangles, then the triangles:

**SA = 2(lw)**

**= 2 (7 x 4)**

**= 2 (28)**

**= 56 squared m**

now I find the area of the triangles:

-SA =2 (b x h/ 2)

- but since the formula is multiplied and divided by two, they both cancel out

-SA = b x h

**SA = b x h**

**= 4.8 x 3.2**

**= 15.36 squared m**

now I add the two:

**SA = 56 + 15.36**

**= 71.36 squared m**

-but after adding the two, I have to subtract the area of the two windows

-SA= 2 (0.8 x 0.6)

= 2 (0.48)

= 0.96

**SA = 71.36 - 0.96**

**= 70.04 squared m**

After all the work that's done, the answers are:

Windows =

**4.8 squared metres**Doors =

**3.36 squared metres**Walls = 51.8

**squared metres**Roof =

**70.04 squared metres**

That is how I got all my answers. Sorry if it's kind of confusing and THANKS FOR READING MY SCRIBE

GOOD WORK ELAINE! It took me a while to understand what you did, but I get how you got the answer. You must've done a lot of thinking! The only thing I'd have to say is to add colour, because it got really confusing when everything looked exactly the same and I would scroll up to check for the measurements then I'd have to read things over again to see which was the windows etc. but good job!

ReplyDeleteThanks for posting this it really helped :D

ReplyDelete