Circumference Review

Review What is the relationship between a radius and a diameter? What does a circumference measure? What formulas do we use to calculate circumference? What do we use to represent pi?

Pi Equals? π = circumference/diameter ≈ π ≈ 22/7 or 3 and 1/7 We will use ………. (on and on and on)

Find the Circumference of the circle. BACK

Find the circumference using the diameter. BACK

Calculate the following Using 3.14 for pi. –r = 6 –r = 13 Using 22/7 for pi. –r = 8 –d = 24

Circumference 2 Assignment Use 3.14 for pi 1)r = 4 2)r = 7 3)r = 9 4)d = 15 5)d = 22 6)d = 30 Use 22/7 for pi 1)r = 4 2)r = 7 3)r = 9 4)d = 15 5)d = 22 6)d = 30

Area of a Circle

Area The number of square units the figure covers

Area of a Circle

Find the Area of the circle.

Practice Problems Using 3.14 for pi –r = 6 –d = 14 Using 22/7 for pi –r = 8 –d = 24

Area of a Circle1 Assignment Use 3.14 for pi 1)r = 4 2)r = 9 3)d = 16 4)d = 22 Use 22/7 for pi 1)r = 4 2)r = 9 3)d = 16 4)d = 22

Area of a Circle