Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Geometry

Question:

Two chords AB and CD of lengths 4 cm and 10 cm respectively are parallel and are on the same side of the centre O of a circle. If the distance between chords is 3 cm, then what is the diameter of the circle?

Options:

\(\sqrt {29}\)

2\(\sqrt {29}\)

3\(\sqrt {29}\)

4\(\sqrt {29}\)

Correct Answer:

2\(\sqrt {29}\)

Explanation:

Let OP = x cm

In ΔBQO:

(BO)2 = (BQ)2 + (QO)2 = (2)2 + (3 + x)2

In ΔCPO:

(CO)2 = (CP)2 + (PO)2 = (5)2 + (x)2

Hypotenuse of ΔBQO and ΔCPO are same = radius

Therefore,

⇒ (2)2 + (3 + x)2 = (5)2 + (x)2

⇒ 4 + 9 + x2 + 6x = 25 + x2

⇒ 6x = 12

⇒ x = 2

(CO)2 = (CP)2 + (PO)2 = (5)2 + (2)2 = 25 + 4 = 29

OC = \(\sqrt {29}\) = radius

diameter = 2 × OC = 2\(\sqrt {29}\)cm