SSC CGL 2019 PYQ — Question 65

SSC CGL - 6th June 2019 - Shift 1 • Quantitative Aptitude • Q65

ABCD is a cyclic quadrilateral whose diagonals intersect at P. If AB = BC, ∠DBC = 70° and ∠BAC = 30°, then the measure of ∠PCD is:

Show answer & explanation

Correct answer: A

Explanation

The correct answer is Option 1 i.e. 50°

Concept

Understanding

Application

In a cyclic quadrilateral, opposite angles are supplementary angles. 

 

Angles made by the same cord of a circle are equal. 

Given:

AB = BC, ∠DBC = 70° and ∠BAC = 30°

Since AB = BC

So, ∠BAC = ∠BCA = 30°

And

∠DBC = ∠DAC = 70° (Angles made by same cord CD)

∠BAD +∠BCD = 180°

100° + ∠BCD = 180°

∠ BCD = 80°

So, angle ∠PCD = 80 – 30 = 50°