SOLUTION: The length of a rectangle is three times its width, the perimeter of the rectangle is 24cm. Calculate the area.

Algebra ->  Rectangles -> SOLUTION: The length of a rectangle is three times its width, the perimeter of the rectangle is 24cm. Calculate the area.      Log On


   

Question 1154520: The length of a rectangle is three times its width, the perimeter of the rectangle is 24cm. Calculate the area.
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +x+ = the width, W
+3x+ = the length, L
----------------------------
The formula for perimeter, P, is:
+P+=+2L+%2B+2W+
+P+=+2%2A%28+3x+%29+%2B+2x+
+24+=+6x+%2B+2x+
+8x+=+24+
+x+=+3+
and
+3x+=+9+
--------------------
Let +A+ = the area
+A+=+W%2AL+
+A+=+x%2A3x+
+A+=+3%2A9+
+A+=+27+
-------------------------
check:
+P+=+2%2A%28+3x+%29+%2B+2x+
+P+=+2%2A9+%2B+2%2A3+
+P+=+18+%2B+6+
+P+=+24+
OK