Trapezoid ABCD AB parallel DC ad = BC AE, BF are the height of two waist respectively, and AE, BF intersect with point o Let BAE = x and C = y find out and prove the relation between X and y

Trapezoid ABCD AB parallel DC ad = BC AE, BF are the height of two waist respectively, and AE, BF intersect with point o Let BAE = x and C = y find out and prove the relation between X and y

∵AB‖DC ∴∠EBA=∠C
And ∵ ∠ AEB = 90 ∵ C + ∠ BAE = 90
So y = 90-x
(I can't use the condition of BF ⊥ AD)