What are some words you remember that go with circle?

Get out 5 pieces of paper and fold like a hamburger.

Standards G.6.1, G.6.2, G.6.7

A Circle is the shape that is produced when you plot all of the points which are the same distance away from a center point.

E

Circles are referred to by the center point. This circle would be

called ๏E

Center

A

B

Chord – Any line segment drawn inside a circle. This is chord AB. A chord always touches 2 edges of the circle.

C

Radius – Any line segment drawn from the center to a point on the circle. This is radius DC

D

X

Y Diameter – Any chord which runs through the center of the circle. This is diameter XY.

Notice: A radius is always half of a circle’s diameter

The perimeter of a circle is called its circumference

Formula: C = 2r (or d) ≈ 3.14

r = the circle’s radius

Note: You may leave a circumference answer in terms of unless you are asked for a decimal approximation.

1. Find mQT2. Find mUY3. Find mQY4. Name a radius5. Name a diameter6. Name a chord7. Name this circle8. Find the circumference

Q

W

X

Y

U

Z

10

T10

20

10

QW, QU, QT, QY

UY

XZ, UY

๏ Q

2 (10) (10) 2020

EX Y F Z

G

The diameters of ๏X, ๏Y, and ๏Z are 22, 16, and 10 respectively.

1.) Find mEX

2.) Find mEY

3.) Find mXF

4.) Find mGY

11 8 5

11

19

113

13

5

Find the missing measures in the following table

RadiusRadius DiameterDiameter CircumferencCircumferencee

44 ?? ??

?? 1212 ??

?? ?? 70.270.2

1.)

2.)

3.)

8 8ππ

6 12ππ

C = d

22.411.2

70.2 = d

Find the circumference.

Find the circumference.