Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Geometry

Question:

In the given figure, PQRS is a square whose side is 12 cm. PQS and QPR are two quadrants. A circle is placed touching both the quadrants and the square as shown in the figure. What is the area (in cm2) of the circle ?

Options:

\(\frac{33}{14}\)

\(\frac{33}{48}\)

\(\frac{99}{56}\)

\(\frac{99}{48}\)

Correct Answer:

\(\frac{99}{56}\)

Explanation:

Let radius of circle = r

∴ OA = 12 - r, OQ = 12 + r

In ΔOAQ

(OQ)2 = (OA)2 + (AQ)2

(12 + r)2 = (12 - r)2 + 62

144 + r2 + 24r = 144 + r2 - 24r + 36

       48r = 36

          r = \(\frac{36}{48}\)

          r = \(\frac{3}{4}\)

and area of circle = \(\pi \)r2

= \(\frac{22}{7}\) × \(\frac{3}{4}\) × \(\frac{3}{4}\) = \(\frac{99}{56}\) cm2