1. Circles Grade 6 3.02 Identify parts of a circle

2. Parts of a Circle center F Use the center to name a circle. Circle F F

3. Parts of a Circle chord diameter radius

4. Formulas Radius/diameter Circumference radius = ½diameter r = ½ d diameter = 2(radius) d = 2r C = 2∏ror C = ∏d

5. Circumference The circumference of a large wheel is 12.5 meters. How would you find the diameter of the wheel? Step 1: Use the formula C=πd and substitute the values you know. Step 2: Solve the equation 12.5 = 3.14d so 12.5/3.14 = d

6. Circle Problem A circle has a radius of 15 cm. How do you find the diameter and circumference of the circle? What is the maximum length of any chord on the circle? Step 1: Use the formula and substitute the values you know. Step 2: C=πd so C = 3.14 x 30 (2 x 15)

7. Circle Problem If a chord of a circle measures 8 cm., what is the minimum area the circle could have? Step 1: Use the formula for area of a circle and substitute the values you know. Step 2: A chord of 8cm. means that the diameter can not be larger than 8. If we use 8 as d, than the radius cannot be larger than 4. So, A = πr² and A = 3.14 x 16

8. Circles in the coordinate plane Using the graph paper provided, plot the following: Circle C with a center at (4,0) and a radius of 2. What is the diameter of Circle C? What is the circumference of Circle C? What is the area of Circle C?