Answer:
Step-by-step explanation:
Angle <em>ABP</em> and angle <em>MAB</em> are corresponding angles.
Corresponding angles are equal.
Angle <em>ABP</em> = 50 degrees
Angle <em>CBP</em> and angle <em>BCQ</em> are corresponding angles.
Corresponding angles are equal.
Angle <em>CBP</em> = 20 degrees
Angle <em>ABC</em> is the sum of angles <em>CBP</em> and <em>ABP.</em>