Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Geometry

Question:

In ΔABC, D is a point on AC such that AB = BD = DC.  If ∠BAD = 60°, then the measure of ∠B is?

Options:

80°

90°

40°

60°

Correct Answer:

90°

Explanation:

∠BAD = ∠BDA  (because AB = BD)

and  ∠BDA = ∠CBD + ∠BCD = x + x = 2x

2x = 60° 

x = 30°

∠ABD = 180° - 60° - 60° = 60°

∠B = 60° + x = 60° + 30° = 90°