A trapezoid's parallel sides are 8 decimeters and 18dm, the other sides are 8.1dm and 5dm.
How do I find surface area and height of the trapezoid? We're studying trigonometry at the moment, but I can't think of any way to solve it this way, so I need your help, thanks.

Anyone please?

When only the side lengths are known, you can use this formula:



where and: a > c

Then using:



and therefore:



you can calculate the height.

Okie, thanks a lot :).