1.   investigate the relationship between the diameter and circumference of a circle.

2.   circumference – the perimeter of a circle   diameter – the distance across a circle through the center   radius – half the diameter Circumference & Diameter

3. Symbol for pi  π π = circumference ÷ diameter = 3.14 Formula for finding the circumference of a circle is: C = π x d Want some pi?

4.   Calculate the circumference of a circle with a diameter of 8.15 cm.   C = π x d   C = 3.14 x 8.15   C = 25.59 cm Example

5.   Calculate the circumference of a circle with a diameter of 6.5 cm.   C= 20.41   Calculate the circumference of a circle with a diameter of 62.5654 cm.   196.46 Your Turn

6.   What do you do if you know the circumference and are trying to find the diameter?   Use the following formula: d = c ÷ π Other Way

7.   Page – 211 – 213 # 1, 2, 3, 4, 5, 8, 9, 12, 13, 15 Work on