SSC CGL 2019 PYQ — Question 62

SSC CGL - 4th June 2019 - Shift 2 • Quantitative Aptitude • Q62

In ΔABC, AD ⊥ BC and BE ⊥ AC. AD and BE intersect each other at F. If BF = AC, then the measure of ∠ABC is:

Show answer & explanation

Correct answer: C

Explanation

Correct Answer is option 3 i.e. 45°

Concept

Understanding

Application

AA property: If 2 angles of 2 triangles are equal, they must be similar triangles.

Given 

AD ⊥ BC and BE ⊥ AC

BF = AC

Here ∆AEF ~ ∆BDF (By AA)

So, ∠DBF = ∠EAF

Now,

∠DBF = ∠CAD and ∠BDF = ∠ADC

Hence, ∆BDF ~ ∆ADC (By AA)

BD/AD = DF/DC = BF/AC

Since, BF = AC

⇒ BD = AD and DF = DC

Hence, ∠ABD = ∠BAD = 45°