Chapter 6 Cirlces

 

Circles Unit 6.2

Key Ideas:

Circumference

Diameter

Radius

3.14

Previous Knowledge

·     Formulas for Area and Surface Area

Circumference of a Circle

The perimeter of a circle is called the circumference.  The circumference is the distance around the circle.
The circumference, C, of a circle is given by the formula   where r is the radius of the circle, and
Example 4 A circular swimming pool has a radius of 14 m.  Find the circumference of the pool. Solution:
So, the circumference of the pool is 88 m.
Note: Example 5 A circular flower-bed has a radius of 9 m.  Find the circumference of the flower-bed. Solution:
So, the circumference of the flower-bed is 56.5487 m.

HEADS UP

Independent 8 minutes (shields up), then calculate your score.

Video

http://www.khanacademy.org/math/geometry/basic-geometry/circum_area_circles/e/radius_diameter_and_circumference

Independent 20 minutes

#1-5 on page 245

Group 20 minutes

#6-9 on page 246

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Heads Up

-5, -3, -2, 1, 1, 2, 4, 5, 6, 8, 13, 13, 14, 16,

Area of a Circle Unit 6.3

Key Ideas:

Circumference

Diameter

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Area of a Circle Unit 6.3

Key Ideas:

Info Page

http://www.wikihow.com/Calculate-the-Area-of-a-Circle

Video

http://www.youtube.com/watch?v=OBnKYoOpdsM

Previous Homework

Page 250 # 1-4 / Page 250 – 251 # 5-8

Independent 10 minutes

Page 252 # 1, 2, 4

Group Work 20 Minutes

Page 252 # 5, 7, 11

Math Reflection

Quiz Thursday on Circumference and Area of Circles

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Surface Area of a Cylinder continued

http://math.about.com/od/formulas/ss/surfaceareavol_3.htm

Video Link

http://www.youtube.com/watch?v=sPqIqGeF4fc

http://www.youtube.com/watch?v=sPqIqGeF4fc

Independent

Worksheet 1, 3 on the bottom of page 288, 5, 7, 9 on page 289

 

Radius

3.14