SSC CGL 2019 PYQ — Question 57

SSC CGL - 6th June 2019 - Shift 2 • Quantitative Aptitude • Q57

ABDC is a parallelogram in which diagonals AD and BC intersect at O. AE and DF are perpendicular on BC at E and F, respectively. Which of the following is not true?

Show answer & explanation

Correct answer: A

Explanation

The correct answer is option 1 i.e. ∆ ADC ≅ ∆ ABD

Understanding

Application

In ∆ABC and ∆DBC:

AC = BD, AB = DC and BC is the common side

hence, triangles are congruent.

 

In ∆ AEO and ∆ DOF:

∠AOE = ∠DOF (vertically opposite angle)

∠AEO = ∠DFO (both 90°)

And AO = OD (BC bisects AD)

Hence, the triangles are congruent

 

In ∆ AEB and ∆ DFC:

∠DFC = ∠AEB

∠ABE = ∠DCF

CD = AB

Hence, the triangles are congruent

In ∆ ADC and ∆ ABD

AC = BD

AD = AD

And CD = BA

Hence ∆ ADC is congruent to ∆ DAB. But not congruent to ∆ ABD

Hence statement 1 is not true.