It is known that in the isosceles trapezoid ABCD, ab = CD, ad is parallel to BC, point E is a point outside the trapezoid, and EA = ed Draw your own picture. Oh, Sheila!

It is known that in the isosceles trapezoid ABCD, ab = CD, ad is parallel to BC, point E is a point outside the trapezoid, and EA = ed Draw your own picture. Oh, Sheila!

Analysis, to prove that the triangle EBC is isosceles triangle, then e must prove on the vertical bisector of BC: connect be and CE, because EA = ed, so the triangle ead is isosceles triangle, so the angle ead = angle EDA, because ABCD is isosceles trapezoid, so the angle DAB = angle ADC, and add the above two equal angles to get the angle EAB = angle EDC, and because EA = ed, ab =