question_answer

In the expression, surface area = \[4\pi {{r}^{2}}\], the factor 4 is an exact number. How many number of significant figures are there in the factor 4?

Answer:

                In the expression, surface area = \[4\pi {{r}^{2}}\], the factor 4 is an exact number-which has infinite number of significant figures. It can be written as 4 or 4-0 or 4-00 or 4-000 and so on.