MathDB

4

Part of 2010 Grand Duchy of Lithuania

Problems(1)

BK = 2DC wanted, < ABC = < KAD = < AKD, < CAB = 90^o

Source: 2010 Grand Duchy of Lithuania, Mathematical Contest p4 (Baltic Way TST)

10/2/2020
In the triangle ABCABC angle CC is a right angle. On the side ACAC point DD has been found, and on the segment BDBD point K has been found such that ∠ABC=∠KAD=∠AKD\angle ABC = \angle KAD = \angle AKD. Prove that BK=2DCBK = 2DC.
geometryequal anglesright triangleequal segments