Given: m || n, m∠1=65∘, m∠2=60, and BD−→bisects ∠ABC.
Prove m∠6=70∘
It is given that m∥n, m∠1=65∘,m∠2=60∘, and BD−→bisects ∠ABC. Because of the triangle sum theorem,
∘m∠3=55∘ . By the ________, ∠3≅∠4, so m∠4=55∘. Using the ________,
m∠ABC=110∘. m∠5=110∘ because vertical angles are congruent. Because of the ________
m∠5+m∠6=180∘. Substituting gives 110∘+m∠6=180∘. So, by the __________, m∠6=70∘.
Options: [Definition of bisector], [Transitive property of equality],[angle addition postulate],
[same side interior angles theorm] , [corresponding angles postulate], [alternate interior angles postulate], [subtraction property of equality], [linear pair of postulate]
