Results 1 to 3 of 3

Math Help - Trapezoid problem

  1. #1
    Newbie
    Joined
    May 2010
    Posts
    13

    Trapezoid problem

    Lot 21 is a trapezoid with the two bases perpendicular to the road. The scale drawing below uses 1/2 inch = 40 ft.



    A) 1/2 acre
    B) 2 acres
    C) 2 1/2 acres
    D) 3 acres

    So here's how I try to solve it:

    A = 1/2 x 4 (5 + 3 1/2)
    A = 1/2 x 20 x 8 1/2
    A= 85

    What am I doing wrong? What steps do I take?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Eater of Worlds
    galactus's Avatar
    Joined
    Jul 2006
    From
    Chaneysville, PA
    Posts
    3,001
    Thanks
    1
    Did you use your scale that 1/4 inch equals 40 feet?.

    b1: How many 1/2 inches are in 3.5 inches?. 7

    7*40=280

    b2: How many half inches are in 5 inches?. 10

    10*40=400

    Proceed in that fashion and you should be OK. It's like that other problem I stepped through involving scales.

    Find the square feet form this and then divide by 43,560 to find the acres.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Eater of Worlds
    galactus's Avatar
    Joined
    Jul 2006
    From
    Chaneysville, PA
    Posts
    3,001
    Thanks
    1
    In real-life, scales on blueprints are usually given as 1" = however many feet.

    If 1/2 inch is 40 feet, then 1 inch is 80 feet. So, 5 inches would be 400 feet.

    You could proceed this way.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Isosceles trapezoid problem
    Posted in the Geometry Forum
    Replies: 36
    Last Post: December 15th 2010, 08:40 AM
  2. Trapezoid problem I know the answer to
    Posted in the Geometry Forum
    Replies: 1
    Last Post: October 20th 2010, 04:52 PM
  3. Please help my with a trapezoid-problem
    Posted in the Geometry Forum
    Replies: 1
    Last Post: January 22nd 2009, 10:04 PM
  4. Trapezoid problem
    Posted in the Algebra Forum
    Replies: 0
    Last Post: January 22nd 2009, 09:09 AM
  5. Trapezoid Problem
    Posted in the Geometry Forum
    Replies: 4
    Last Post: December 3rd 2006, 02:19 PM

Search Tags


/mathhelpforum @mathhelpforum