Sign in
Please select an account to continue using cracku.in
↓ →
Join Our JEE Preparation Group
Prep with like-minded aspirants; Get access to free daily tests and study material.
ADC and ABC are triangles such that $$AD=DC$$ and $$CA=AB$$. If $$\angle CAB=20^\circ$$ and $$\angle ADC=100^\circ$$, without using trigonometry, prove that $$AB=BC+CD$$.
Correct Answer: 0
Extend BC to a point E such that $$CE=CD$$, making triangle CED equilateral since the base angles work out to $$60^\circ$$. Joining AE and tracking the resulting angles shows triangle ABE is isosceles with $$AB=BE$$. Since $$BE=BC+CE=BC+CD$$, this gives $$AB=BC+CD$$.
Was this solution helpful?
Predict your JEE Main percentile, rank & performance in seconds
Educational materials for JEE preparation