In rectangular trapezoid ABCD, AD / / BC, ∠ ABC = 90 °, de ⊥ AC at point G, intersects the extension point e of AB, and AE = AC, if ad = DC = 2, find the length of DF How to prove that the DAC is 30 degree

In rectangular trapezoid ABCD, AD / / BC, ∠ ABC = 90 °, de ⊥ AC at point G, intersects the extension point e of AB, and AE = AC, if ad = DC = 2, find the length of DF How to prove that the DAC is 30 degree

It is proved that in triangle AED and triangle CED, ad = DC, angle AEB = angle CDE, ed = ed, then: Triangle AED and triangle CED are congruent. Then: AE = EC, AE = AC, AE = EC = AC, angle BAC = 60, angle BAE = 90, then: angle DCA = angle DAC = 30, AD / / BC, then: angle ACB = angle DCA = 30, and: de ⊥ AC is equal to