Question

What is the correct classification for ∠BEC?

straight

obtuse

right

acute

Answer 1

All these angles must add up to 180° because they are on a straight line. Make ∠BEC = x.

55 + x + 34 = 180
Combine like terms.

89 + x = 180
Subtract 89 from both sides.

x = 91

Since ∠BEC is greater than 90°, it is classified as an obtuse angle.