SOLUTION: a rectangle is three times as long as it is wide.If it has a perimeter of 64cm,find its area

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Question 698458: a rectangle is three times as long as it is wide.If it has a perimeter of 64cm,find its area
Answer by Stitch(470) About Me  (Show Source):
You can put this solution on YOUR website!
The perimeter of a rectangle is given by P = 2L + 2W
L = lengh
W = Width
Equation 1: L+=+3W
Equation 2: 64+=+2L+%2B+2W
Plug 3W into equation 2 for L
Equation 2: 64+=+2L+%2B+2W
64+=+2%2A%283W%29+%2B+2W
Simplify
64+=+6W+%2B+2W
Combine like terms
64+=+8W
Divide both sides by 8
highlight%288+=+W%29
Now plug 8 into equation 1 for W
Equation 1: L+=+3W
L+=+3%2A%288%29
highlight_green%28L+=+24%29
The area of a rectangle is given by A = L * W
A = 24cm * 8cm
A = 192 square cm