(1) Because LACB=90 degrees and DC = BC, LD = LABC；; ; And because LE=LABC and LE=LD, this is proved.

(2) The Pythagorean theorem formula of AC2+BC2=AB2 is established, and the lengths of AC and BC are obtained by solving the unary quadratic equation with known conditions.

Solution of AE length: It is proved that the triangle DCE is similar to the triangle DAB, and the DE length can be obtained. Given the length of AD (AD = AB) and AE = DE-AD, it is proved that.

The specific calculation will be solved by itself. That's the idea. Let's go