SOLUTION: pre-algebra/geometry: perimeter of rectangle is 20 ft. the width of rectangle is 4 ft less than length. find the dimentions of the rectangle. then find its area.

Algebra ->  Customizable Word Problem Solvers  -> Misc -> SOLUTION: pre-algebra/geometry: perimeter of rectangle is 20 ft. the width of rectangle is 4 ft less than length. find the dimentions of the rectangle. then find its area.       Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 395355: pre-algebra/geometry: perimeter of rectangle is 20 ft. the width of rectangle is 4 ft less than length. find the dimentions of the rectangle. then find its area.
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

perimeter of rectangle P is 20+ft
the width of rectangleb is 4+ft less than length a
or
P+=+20+ft
b+%2B+4ft+=+a

find the dimentions of the rectangle
P+=+2%28a%2Bb%29=+20+ft
2%28%28b+%2B+4ft%29+%2Bb%29%2F2=+20%2F2+ft
%282b+%2B+4ft%29=+10+ft
2b+=+10+ft+-+4ft
2b+=+6+ft
2b%2F2+=+6+ft%2F2
b+=+3ft..........width
now find the length a
3ft+%2B+4ft+=+a
7ft+=+a.........length

then find its area A
A+=+ab
A+=+7ft%2A3ft
A+=+21ft%5E2