I constructed a trapezoid with equal legs that does not have equal base angles. Am not nitpicking 0.1 degree. But in other tests, the angles are equal to 3 decimal places in the display. The only difference here is that the trapezoid was first drawn on a construction plane.
Oops, I misspoke a bit; the angles are not all exactly equal in my test case but no big deal. Including the original with all 4 angles shown FYI.
You should add horizontal/vertical constraints to the top and the bottom side. (Or a parallel constraint between them.) Otherwise, it is just a quadrilateral with two equal sides, not a trapezoid.
Thank you for your responsiveness. Somehow I thought a line snapping to a grid would auto-insure horizontal/parallel condition. I guess being explicit is always best.