In the diagram, line m is parallel to line n.
What is the measure, in degrees, of angle ABC?

Answer:
m∠ABC = 55°
Step-by-step explanation:
m∠BAC = 50° because ∡BAC ≅ ∡DCA
since there are 180° in ΔABC the m∠ABC = 180-(75+50) which equals 55°