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MathNet 2017-part-03 — 176 problems (EN–VI) Question 109

Math Olympiad Vault · MathNet 2017-part-03 — 176 problems (EN–VI)

Question 109

Quadrilateral $ABCD$ and point $T$ in its interior is given such that $AC$ is the angle bisector of $\widehat{BCD}$ and
$$
\widehat{ABC} - \widehat{ATD} = \widehat{DAC}, \quad \widehat{ADC} - \widehat{ATB} = \widehat{BAC}.
$$
Prove that $\widehat{BAT} = \widehat{DAC}$.