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]: .