Subject: General Aptitude · Chapter: Area · Exam: 2009 · Marks: · Difficulty:
If the perimeter of a square is equal to the radius of a circle whose area is 39424 sq. m. What is the are area of the square?
(a)441 sq.m
(b)784 sq.m
(c)1225 sq.m
(d)Cannot be determined
(e)None of these
Answer
Answer (as printed): B
Explanation
Let the radius of the circle be $R$ cm. Then , $$\pi R^{2}=39424 \Rightarrow R^{2}=39424 \times \frac{7}{22}=12544 \Rightarrow R=112 \mathrm{cm} .$$ Perimeter of the square $=112 \mathrm{cm}$. Side of the square $=\left(\frac{112}{4}\right) \mathrm{cm}=28 \mathrm{cm}$. ∴ Area of the square $=(28 \times 28) \mathrm{cm}^{2}=784 \mathrm{cm}^{2}$.