SOLUTION: one side of a rectangle is 3cm longer than the other. The area of the rectangle is twice its perimeter .Find the dimensions of the rectangle Thank you

Algebra.Com
Question 1200723: one side of a rectangle is 3cm longer than the other. The area of the rectangle is twice its perimeter .Find the dimensions of the rectangle Thank you
Answer by ikleyn(52781)   (Show Source): You can put this solution on YOUR website!
.
one side of a rectangle is 3cm longer than the other.
The area of the rectangle is twice its perimeter .
Find the dimensions of the rectangle Thank you
~~~~~~~~~~~~~~~~~~

x = one side
x+3 = the other side.


The area = x*(x+3)

The perimeter = 2(x + (x+3)) = 2(2x+3) = 4x + 6


Equation

    x*(x+3) = 2(4x + 6)

    x^2 + 3x - 8x - 12 = 0

    x^2 - 5x - 12 = 0

     =  = .


    The unique solution to the problem is the positive root x =  = 6.772001873.


The dimensions are 6.772001873 cm  and  9.772001873 cm.


CHECK.  The area is  6.772001873*9.772001873 = 66.17601499 cm^2;  

        the perimeter is  2*(6.772001873+9.772001873) = 33.08800749 cm.

        the ratio of these numbers is   = 2.000000000302  close enough to 2.

Solved.



RELATED QUESTIONS

a rectangle is 3cm longer than its wide. the perimeter is 66cm.find the... (answered by Troy7477)
The perimeter of a rectangle is 48cm. The length of a rectangle is 3cm longer than twice... (answered by math_tutor2020)
The length of a rectangle is 3cm longer than its width. If the perimeter of the... (answered by mananth)
The length of a rectangle is 3cm longer than its width. If the perimeter of the rectangle (answered by josgarithmetic)
A square has an area of 169 centimeters it's side is 3cm longer than the width of a... (answered by macston)
The perimeter of a rectangle is 32cm. One side is 10 cm longer than the other side. Find... (answered by fafa)
One side of a rectangle is one foot longer than twice the other side, and the perimeter... (answered by Fombitz)
One side of a rectangle is 3 cm longer than twice the shorter side,and the area is... (answered by Alan3354,josgarithmetic)
The length of a triangle is 3cm longer than its width. If the perimeter of the rectangle... (answered by JulietG)