Investigation 3 Area and Circumference of Circles Circles and using pi

Homework Book A 8,9,10,11,24,26,28,30,31,48 B 8,9,11,21,22,26,28,30,31,34,50 IXL W1 and W5

Vocab Diameter Distance across a circle that goes through the center Radius half the diameter, goes from center to any point on circle Circumference distance around a circle Center Point that is equidistant from the side (circle), inside

Invest 3.1 Going Around in Circles: Circumference What is the relationship between the diameter or radius of a circle and its circumference?

Notes Understanding the terms Diameter = 2 times radius Radius = ½ diameter Circumference = 2*pi*radius or pi*diameter

Example Pg 51 problem 3.1

Homework You should be able to have the following problems finished 8 and 9

Invest 3.2 Pricing Pizza: Connecting Area, Diameters and Radius How does the area of a circle increase as the circle’s radius and diameter increase?

Notes Finding the area of a circle Area = pi* radius^2 Know how to work forwards and backwards with circumference to get radius to then get area

Example

Example Pg 53 problem 3.2

Homework You should be able to have the following problems finished A 10, 11, 48 B 11,21,22

Invest 3.3 Squaring a Circle to Find Area What is the relationship between the area of a circle and its radius?

Example Pg 54 problem 3.3

Homework You should be able to have the following problems finished A 24,26,28 B 26,28,50

Invest 3.4 Connecting Circumference and Area What is the relationship between the circumference and area of a circle?

Notes Pi is approximately 3.14, symbol Be able to go form Circumference to area and vice versa

Example Video Pg 57 problem 3.4