We want to find the area of the coin that has a diameter of 30 millimeters.
Remember that the area of a circle with radius r is calculated using the formula below.
A=Ï€ r^2
Here, we know that the diameter of the coin is 30mm. To use the formula, we first need to divide the diameter by 2 to determine the radius.
r=30/2= 15
Let's substitute 15 for r in the formula and calculate A. We will use 3.14 for π.
A=Ï€ r^2
r= 15
A=Ï€( 15)^2
Calculate power
A=Ï€(225)
π ≈ 3.14
A≈ 3.14* 225
Use a calculator
A≈706.5
The area of the coin is approximately 706.5mm^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.
