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# Area & perimeter word problem: table

Sal solves for the dimension of a table. Created by Sal Khan.

## Want to join the conversation?

• What if the length and width are decimals?
• If the length and width are decimals, you multiply them anyway to get the right answer. You could convert them into fractions, but that's a lot harder to do. Fractions are another story...
• I dont get any of this and ive been working on it for weeks
• me neither. :P
• how did u get 20 for the width and 24 for the length
• There is nowhere in the video that those assignments are made. In the problem statement, the perimeter is 20 feet, and the area is 24 square feet. Also, at roughly , Sal has the equations you will need to find length and width.
• A rectangular field is enclosed by 320 feet of fencing. If the length of the field is 6 feet more than its width, what is its length, in feet?
• First, pick variables for each side and the perimeter:
l = length
w = width
p = perimeter

We know that the outside of the rectangle (or perimeter) is w + l + w + l, and we also know that it is 320 feet:
p = w + l + w + l
p = 2w + 2l
320 = 2w + 2l

We also know that the length is 6 more than the width:
l = 6 + w

So now we can plus this value for l into the equation we got above to solve for w:

320 = 2w + 2l
320 = 2w + 2(6 + w)
320 = 2w + 12 + 2w
320 = 4w + 12
etc.

Once you have solved for w, you can plug that value back into this equation to find l:
l = 6 + w

Finally, double check that the values you found for l and w are valid by plugging them into this equation:
320 = 2w + 2l
(Double w plus double l should equal 320.)

Hope this helps!
• if i took a wire of 44m and bent it into a shape of a circle.how i find its radius and area of circle.if i bent same wire in the shape of square what is the measure of each side
• If your wire is 44m and it has been bent into a circle, then the 44m is the circumference of the circle.
Use the formula for circumference to find the radius.
Circumference = 2 Pi r; or 44 = 2 Pi r
Divide 44 by 2 Pi, and you get r.

To find the area, use your value of r in the area formula for a circle: Area = Pi r^2

If your wire is bent into a square, then the 44 becomes the perimeter of the square. Use the formula for perimeter to find the length of one side: Perimeter = 4x where "x" is the length of 1 side. Or, with your info: 44 = 4x

See if you can finish the calculations. If you get stuck, comment back.
• Can't the width and the length be switched and you get the same answer?
• Yes you will have the same result but the longer side is always the length and the width is always the shorter side. So no you can not switch the sides.
• I don't get it