SSC CHSL 2020 PYQ — Question 55

SSC CHSL - 13th October 2020 - Shift 2 • Quantitative Aptitude • Q55

If in the following figure (not to the scale), ∠ACB = 135o and the radius of the circle is 2√(2) cm, then the length of the chord AB is:

Show answer & explanation

Correct answer: A

Explanation

The correct answer is Option 1 i.e 4 cm

Understanding Application
We will property of cyclic quadrilateral in which  Sum of the opposite angle of cycle quadrilateral is 180o

In quadrilateral ACBD, ∠ACB & ∠ADB are opposite so the sum would be 180o.

⇒ ∠ADB = 180 - 135 = 45o

The angle at the center of a circle is twice the angle at the circumference.

Let the center of the circle be E then

⇒ ∠ACB = 2 × ∠ADB

⇒ ∠ACB = 90o

In the right-angle triangle ABE

AB2 = AE2 + BE2

AB = √{2(2√2)2}

AB = 4cm