Let's find the perimeter of this semicircle. The straight side is the diameter of a full circle. The distance around the curved part is one-half the circumference of the circle. The circumference C of a circle with diameter d is calculated using the formula below.
C=Ï€ d
From the figure, we know that the diameter of the circle is 7cm. We can substitute 7 for d in the formula and then calculate C. We will use 3.14 as an estimate for π.
The circumference of the full circle is approximately 21.98cm. We divide this circumference by 2 to find the distance around the curved part.
21.98÷ 2 = 10.99
Finally, we can add 10.99 and the straight side 7 to find the perimeter.
10.99+7=17.99
We found that the perimeter is approximately 17.99cm.
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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.
