1 / 10

Circles and Circumference

Circles and Circumference. Lesson 10-2. Vocabulary. A circle is a plane figure that consists of a set of points that are equidistant from a given point called the center. The circumference of a circle is the distance around it. Identifying the Parts of a Circle.

virgil
Télécharger la présentation

Circles and Circumference

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Circles and Circumference Lesson 10-2

  2. Vocabulary • A circle is a plane figure that consists of a set of points that are equidistant from a given point called the center. • The circumference of a circle is the distance around it.

  3. Identifying the Parts of a Circle A radius is a line segment that connects the outside of the circle to its center.

  4. A diameter is a line segment with both endpoints on the circle that passes through the center.

  5. Numerical Relationships • A radius is exactly one-half of a diameter. • Therefore a diameter is twice a radius. If the radius is 5.5 cm, then the diameter is ___________ cm. 11 5.5 cm

  6. Circumference Formulas C = πd C = 2πr

  7. Circumference • Remember, circumference is the distance around the circle. • If you divide a circle’s circumference by its diameter, you always get the same irrational number – pi (symbol: π) • This is true of every circle. • We estimate pi to be 3.14 or the fraction 22/7.

  8. Example C = πd C = (3.14)(41) 41 m C = 128.74 m We substitute 3.14 in for pi.

  9. Example C = 2πr C = (2)(3.14)(6) 6in C = 37.68in We substitute 3.14 in for pi.

  10. Practice Time P 531 # 2, 3, 5, 6, 8, 9

More Related