math formula help

[jamesloacher]

I've been asked to write a program with the following stipulations.I don't know what the formula would be.Area or something??

There is a rectangular building.We are to paint all four walls and the ceiling.And decide how much paint it will take.What would be the formula for this?Saying each 100 ft took 1 gallon of paint or something.

[Genesis F5]

You have to use the area formula: (W)idth * (H)eight= (A)rea.

So if a wall is 20 feet wide by 10 feet tall, then the formula will be 20 x 10 = Area.
20 x 10 = 200. 200 / 100ft per gallon = 2 gallons of paint.

[jamesloacher]

Thanks for replying genesis. The program is to ask for all three l,w,h. That is throwing me off.


Given the dimensions of a one-story, rectangular dwelling, you will determine how much paint is needed to paint the interior and how many paintbrushes you’ll need.

Your program will need only four pieces of data: the length, width, and height of the planned structure, and how many coats of paint are to be applied. Assume that the structure is going to be a simple, rectangular playhouse, with no fancy additions, vaulted ceilings, etc. Also, to satisfy your client’s privacy requirement, there will be no windows on any of the walls.

[Genesis F5]

What what they mean by that is they want three dimensional details. Imagine the floor and ceiling as being length / width. So, again, if each was 20 x 10, the total area for the floor and ceiling will be 200 square feet each. Now, each wall will be either W x H or L x H. Since we know the room is a parallelogram (opposite sides are parallel), we know that two walls will be W x H and that two walls will be L X H. So the formula will look like this:

2(L x H) + 2(W x H) + 2(L x W).

And if the L = 20, W = 10, and H = 5, then

2(20 x 5) + 2(10 x 5) + 2(20 x 10) = Total Area.
200 + 100 + 400 = 700.
700 / 100ft per gallon = 7 gallons of paint.

[691175002]

Isn't this along the lines of grade 6 math? Surface area of a cube?
You know, like google?
http://www.google.ca/search?hl=en&sa...G=Search&meta=

[Genesis F5]

Actually, wait. Don't multiply the last one by two. You don't want to paint the floor.

So it's: 2(L x H) + 2(W x H) + (L x W)

[silentweed]

also keep in mind the amount of paint used depends upon how thick you spread it on the walls and how many coats etc... u will need to make certain assumptions if you want to determine the exact amount of paint to be used..