Answer:
Definition of bisector
Angle addition postulate
same side interior angles theorem
subtraction property of equality
Step-by-step explanation:
It is given that m║n, m∠1 = 65°,m∠2=60° and BD --> bisects ∠ABC . Because of triangle sum theorem, m∠3 = 55°. By the definition of bisector , ∠3 ≅∠4, so m∠4= 55°. Using the angle addition postulate , m∠ABC = 110°, m∠5 = 110° because vertical angles are congruent . Because of same side interior angles theorem, m∠5 +m∠6 = 180°. Substituting gives 110°+ m∠6 =180°, so by the subtraction property of equality , m∠6 = 70°.
