Question

Triangle B C D is shown. Line D B extends through point A to form exterior angle A B C. Angle B D C is 67 degrees and Angle C D B is 60 degrees.
What is m∠ABC?

m∠ABC = 60°
m∠ABC = 67°
m∠ABC = 120°
m∠ABC = 127°

Answer 1

Because BA is the extension of BD, ∠ABC is an exterior angle of triangle BCD. An exterior angle equals the sum of the two remote interior angles, so

m∠ABC = 67° + 60° = 127°.

Answer: 127°.