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angle chasing candidate, angle bisector, median, symmetric, circumcircle

Source: Sharygin 2018 final 10 p6

August 15, 2019
geometryangle bisectormediancircumcircleAngle Chasing

Problem Statement

Let AKAK and ATAT be the bisector and the median of an acute-angled triangle ABCABC with AC>ABAC > AB. The line ATAT meets the circumcircle of ABCABC at point DD. Point FF is the reflection of KK about TT. If the angles of ABCABC are known, find the value of angle FDAFDA.
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