Results 1 to 6 of 6

Math Help - Perimeter Problem

  1. #1
    Member
    Joined
    Jan 2009
    Posts
    98

    Perimeter Problem

    AE = 5 cm = base of a triangle. The other 2 sides are equal to 4 cm. Show, by calculation, that FX = 3.12 cm (correct to 2 decimal places), where FX is the height of a triangle (and the angle is 90 degrees).

    Thank you for your help.
    Last edited by JadeKiara; July 5th 2009 at 09:46 PM.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Grandad's Avatar
    Joined
    Dec 2008
    From
    South Coast of England
    Posts
    2,570

    More information please

    Hello JadeKiara
    Quote Originally Posted by JadeKiara View Post
    AE = 5 cm = base of a triangle. Show, by calculation, that FX = 3.12 cm (correct to 2 decimal places), where FX is the height of a triangle.

    Thank you for your help.
    This is clearly incomplete. Can we have the whole question please?

    Grandad
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Jan 2009
    Posts
    98

    Height of a Triangle

    Well, I know the height of a triangle is found by: a^2 = b^2 + c^2.
    How can I show, by calculation, that FX = 3.12 cm (correct to 2 decimal places), where FX is the height of a triangle?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Senior Member Stroodle's Avatar
    Joined
    Jun 2009
    Posts
    367
    So, if the base is 5 cm, and each of the other two sides are 4cm, then you would draw a vertical line from the centre of the base to the vertex. Then using Pythagorus you would have c=\sqrt{4^2-2.5^2} which \approx 3.12

    When c = FX, a = 4cm, and b = 2.5cm (half the base).
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Member
    Joined
    Jan 2009
    Posts
    98
    Ah! How silly of me! I forgot to halve the 5!
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Senior Member Stroodle's Avatar
    Joined
    Jun 2009
    Posts
    367
    Haha. An easy mistake to make
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. perimeter word problem
    Posted in the Algebra Forum
    Replies: 2
    Last Post: September 17th 2011, 08:16 AM
  2. perimeter of garden problem
    Posted in the Geometry Forum
    Replies: 3
    Last Post: August 11th 2010, 09:34 PM
  3. Perimeter Word Problem
    Posted in the Algebra Forum
    Replies: 4
    Last Post: June 29th 2010, 01:13 PM
  4. Perimeter Word Problem
    Posted in the Algebra Forum
    Replies: 2
    Last Post: September 3rd 2009, 02:25 AM
  5. Another Perimeter Problem
    Posted in the Algebra Forum
    Replies: 2
    Last Post: July 5th 2009, 09:47 PM

Search Tags


/mathhelpforum @mathhelpforum