11-12 Significant Figures in Geometry Use geometric formula on the inside front cover of the book to solve these problems.
11 Find the circumference and the area of the circle whose radius is .
The circumference and the area of the circle.
The radius of the circle is .
The formula for the circumference of the circle is,
Here, is the circumference and is the radius of the circle.
The formula for area of the circle is,
Here, is the area of the circle.
The significant figures in a number are one from first nonzero digit to the last nonzero digit when reading from left to right.
When multiplying or dividing, round off the final result so that it has as many as significant digits as in the given values with the fewest number of significant digits.
Substitute for in equation to calculate .