I have a quadrilateral containing two opposite right-angles and two known angles, and two equal known sides, thus:-
I am trying to calculate the area, which appears to be defined, as all the angles and two sides are known. But I can't figure out how to get it. None of the formulae listed here seem to apply.
I've also tried dividing it into two triangles, and also extending the short side to make a larger right triangle, but haven't been able to get anywhere; I keep introducing more ancillary elements than I can find equations for.
Could someone give me a hint?