The Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Math Forum » Discussions » Math Topics » geometry.pre-college

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: Re: Trapazoid geometry
Replies: 0  

Advanced Search

Back to Topic List Back to Topic List  
Rich Kleinschmidt

Posts: 31
Registered: 12/6/04
Re: Trapazoid geometry
Posted: Aug 7, 2006 8:02 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

You can turn it into an algebra problem.

Suppose the trapezoid is ABCD with AB parallel to DC. (It is easier to
visualize if you draw it with AB the longer base and the other base DC "above" AB.)

Sketch the altitudes from both C and D - CE and DF. The length of these
altitudes is what you want - call it x.

Using right triangle trig, you can get the length of AF in terms of x
[tan(A) = x/AF so AF = x/tan(A)]
Similarly you can get the length of EB.
Since DCEF is a rectangle you know that the length of EF = DC.

Now you can write an equation in terms of x stating that the length of AB equals the length of AF + length CD + length EB.

Now you have an algebra problem. The numbers are probably not pretty, but it is just a linear equation.

Rich Kleinschmidt

-------------- Original message ----------------------
From: tompy97 <>
> i have a trapazoid of which i know the lengths of the two paralel sides and
> of the angles, is there any way to find the perpendicular height

Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2018. All Rights Reserved.