Subject: General Aptitude · Chapter: Area · Exam: · Marks: · Difficulty:
Four circles each of radius ' $a$ ' units touch one another. The area enclosed between them in square units is
(a)$\frac{a^{2}}{7}$
(b)$3 a^{2}$
(c)$\frac{6 a^{2}}{7}$
(d)$\frac{41 a^{2}}{7}$
Answer
Answer (as printed): C
Explanation
Required area = (Area of the square - Area of four quadrants each of radius $a$ ) $$\begin{aligned} & =\left[(2 a)^{2}-4 \times \frac{1}{4} \times \frac{22}{7} \times a^{2}\right] \text { sq. units } \\ & =\left(4 a^{2}-\frac{22}{7} a^{2}\right) \text { sq. units }=\left(\frac{6 a^{2}}{7}\right) \text { sq. units. } \end{aligned}$$
Explanation as extracted from the printed page; notation may be imperfect.