MathDB

2016.9.51

Part of Kyiv City MO Juniors 2003+ geometry

Problems(1)

equal angles wanted and given, square (2016 Kyiv City MO 9.5.1 10.4.1)

Source:

9/5/2020
On the sides ABAB and ADAD of the square ABCDABCD, the points NN and PP are selected, respectively, so that PN=NCPN = NC, the point QQ Is a point on the segment ANAN for which ∠NCB=∠QPN\angle NCB = \angle QPN. Prove that ∠BCQ=12∠PQA\angle BCQ = \tfrac {1} {2} \angle PQA.
geometryequal anglessquare