http://www.ck12.org Chapter 10. Perimeter and Area
Example C
A circle is inscribed in a square with 10 in. sides. What is the circumference of the circle? Leave your answer in
terms ofπ.
From the picture, we can see that the diameter of the circle is equal to the length of a side. Use the circumference
formula.
C= 10 πin.Watch this video for help with the Examples above.
MEDIA
Click image to the left for use the URL below.
URL: http://www.ck12.org/flx/render/embeddedobject/52493CK-12 Foundation: Chapter10CircumferenceB
Concept Problem Revisited
The entire length of the crust, or the circumference of the pizza is 14π≈ 44 in.
Vocabulary
Acircleis the set of all points that are the same distance away from a specific point, called thecenter. Aradiusis
the distance from the center to the outer rim of the circle. Achordis a line segment whose endpoints are on a circle.
Adiameteris a chord that passes through the center of the circle. The length of a diameter is two times the length
of a radius.Circumferenceis the distance around a circle.π, or“pi”is the ratio of the circumference of a circle to
its diameter.
Guided Practice
- Find the perimeter of the square. Is it more or less than the circumference of the circle? Why?