Results 1 to 3 of 3

Math Help - Dimensions of Rectangle

  1. #1
    MHF Contributor
    Joined
    Jul 2008
    From
    NYC
    Posts
    1,489

    Dimensions of Rectangle

    A rope 100 feet long is stretched around four posts set at the corners of a rectangle whose area is 576 square feet. Find the dimensions of the rectangle.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Bar0n janvdl's Avatar
    Joined
    Apr 2007
    From
    South Africa
    Posts
    1,630
    Thanks
    6
    Quote Originally Posted by magentarita View Post
    A rope 100 feet long is stretched around four posts set at the corners of a rectangle whose area is 576 square feet. Find the dimensions of the rectangle.
    Since the rope is 100 feet long, then the perimeter of this rectangle must be 100 feet long too.

    So we can say:

    P = 100 = 2L + 2W

    And simplify that to:

    50 = L + W

    And let's rearrange that to:

    L = 50 - W

    ---

    Now let's go to the area (This is going to end up as a simul. equation)

    A = 576 = LW

    Now let's substitute that value we have for the length

    576 = (50 - W)(W)

    576 = 50W - W^2

    W^2 - 50W + 576 = 0

    Solve for W, and subsequently L.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor
    Joined
    Jul 2008
    From
    NYC
    Posts
    1,489

    ok.....

    Quote Originally Posted by janvdl View Post
    Since the rope is 100 feet long, then the perimeter of this rectangle must be 100 feet long too.

    So we can say:

    P = 100 = 2L + 2W

    And simplify that to:

    50 = L + W

    And let's rearrange that to:

    L = 50 - W

    ---

    Now let's go to the area (This is going to end up as a simul. equation)

    A = 576 = LW

    Now let's substitute that value we have for the length

    576 = (50 - W)(W)

    576 = 50W - W^2

    W^2 - 50W + 576 = 0

    Solve for W, and subsequently L.
    Thank you. I had a hard time setting up the right equation.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Rectangle's Dimensions
    Posted in the Algebra Forum
    Replies: 9
    Last Post: April 16th 2010, 07:47 PM
  2. Replies: 1
    Last Post: November 23rd 2009, 06:41 PM
  3. Find Rectangle Dimensions
    Posted in the Pre-Calculus Forum
    Replies: 2
    Last Post: July 30th 2008, 01:21 PM
  4. Dimensions of a rectangle
    Posted in the Geometry Forum
    Replies: 1
    Last Post: February 18th 2008, 10:10 PM
  5. Rectangle Dimensions
    Posted in the Geometry Forum
    Replies: 6
    Last Post: January 25th 2007, 03:19 PM

Search Tags


/mathhelpforum @mathhelpforum