Question

The radius of a disc is 1.2 cm. Its area according to the concept of significant figures will be given by :

• A. $4.5216{cm}^2$
• B. $4.521{cm}^2$
• C. $4.52{cm}^2$
• D. $4.5{cm}^2$

Answer 1

Answer: (D)

$4.5{cm}^2$

Since it's radius is 1.2 cm therefore, according to concept of significant figures:

$area=\pi r^2$

$area=4.5c{m}^2$

Number of significant figures in operands must be equal to answer.