Question

the radius of a circle is 2.02 metre. its area acc to the rule of significant figures is:

1. 12.81
2. 12.819
3. 12.9
4. 12.8​

Answer 1

Given: Radius of Circle = 2.02 m.

To find: Area of the circle according to the rule of significant figures.

Solution:

The radius of Circle = 2.02 m

We know that,

$Area of Circle =\pi r^2\\=3.14 * (2.02)^2\\=3.14*2.02*2.02\\=12.812456m^2$

According to the concept of significant figures,

Minimum Significant Figure = 3

So, Area with proper significant figures = 12.8 m^2.

The area of the circle according to the rule of significant figures is 12.8 (Option D).