Let AD be an altitude of triangle ABC. Prove the following:

If /B = 2 /C < 90°, then |AB| + |BD| = |DC|.

1. Reflect B through D to B'on BC.
2. Construct circle C1 about B'with radius B'C. Note that this circle passes through A.
3. BD = B'D, B'C = AB'= AB.

Posted by broll on 2010-10-28 04:27:42