Subject: General Aptitude · Chapter: Area · Exam: · Marks: · Difficulty:
The area of a circle whose radius is the diagonal of a square whose area is 4 sq. units is
(a)$16 \pi$ sq. units
(b)$4 \pi$ sq. units
(c)$6 \pi$ sq. units
(d)$8 \pi$ sq. units [SSC-CHSL (10+2) Exam, 2015]
Answer
Answer (as printed): D
Explanation
Area of square $=4 \mathrm{sq}$. units. Side of square $=\sqrt{4}=2$ units Diagonal of square $=2 \sqrt{2}$ units Radius of the circle $=2 \sqrt{2}$ units $$\begin{aligned} & \therefore \text { Area of circle }=\pi r^{2} \\ & =\pi \times(2 \sqrt{2})^{2} \\ & =8 \pi \text { sq. units. } \end{aligned}$$
Explanation as extracted from the printed page; notation may be imperfect.