Thread: isosceles trapezoid help

Old guy here who's forgotten everything and needs some help.

I'm trying to make an isosceles trapezoid with a base of 26 inches and an altitude of 16 inches. The sides come in with a 6 degree pitch (84 degree angles). What I'm trying to figure out is the length of the top section that parallels the base. I don't have a clue...

Thanks!

Originally Posted by cluap

Old guy here who's forgotten everything and needs some help.

I'm trying to make an isosceles trapezoid with a base of 26 inches and an altitude of 16 inches. The sides come in with a 6 degree pitch (84 degree angles). What I'm trying to figure out is the length of the top section that parallels the base. I don't have a clue...

Thanks!

1. Draw a rough sketch. (see attachment)

2.

3. Use the tan-function in the small right triangles:



4. Therefore

Hello, cluap!

This requires some Trigonometry.
I hope you're prepared.

I'm trying to make an isosceles trapezoid with a base of 26 inches and an altitude of 16 inches.
The sides come in with a 6° (84° ngles).
What I'm trying to figure out is the length of the top section that parallels the base.

Code:

              B     x     C
              * - - - - - *
             /|           |\
            / |           | \
           /6°|           |  \
          /   |16         |   \
         /    |           |    \
        /     |           |     \
       / 84°  |           |      \
    A * - - - * - - - - - * - - - * D
          a   E     x     F   a
      : - - - - -  26 - - - - - - :

We have isosceles trapezoid
The base is: .
The height is: .

Let: .
Let: .

Then: .
. . Hence: . .[1]


In right triangle

Substitute into [1]: .

Guys - I'm sorry... I forgot to save the link, and I couldn't find this place again! Thanks for the help - you answered my questions in a way I could understand! Thanks for your help.

Take care, Paul