Recall the formula for finding the area of a circle given its radius. The radius is one-half of the diameter.
63.585ft^2
Practice makes perfect
Consider the given shape.
Let's find the area of the circle. The area A of a circle with radius r is calculated using the formula below.
C=Ï€ r^2
From the figure, we know that the diameter of the circle is 9ft. The radius is one-half the diameter of a circle. Let's divide 9 by 2 to find the radius!
9÷ 2=4.5
We found that the radius of this circle is 4.5 feet. We can substitute 4.5 for r in the formula and then calculate A. We will use 3.14 as an estimate for π.
The Area of the circle is approximately 63.585ft^2.
Extra
More About Circles!
Are you interested in learning more about circles? Our Mathleaks original content can teach you all about them! Check out the following resources to see real-world uses for circumference and area, how circles compare to other shapes and why, as well as some higher level topics that you can look forward to learning about in Geometry and Algebra 2.
