Circles (Unit 8) Video – Learn Alberta ?l=0&ID1=AB.MATH.JR.SHAP&ID2=AB.MATH.JR.SHAP.CIRC&lesson=html/ video_interactives/circles/circlesSmall.html

Construct Circles (Unit 8) Student outcome: I will be able to describe the relationship of radius, diameter and circumference Use your compass to draw a circle…Use a ruler to find your radius first! Radius Distance from the centre of the circle to the outside edge…represented by “r” Diameter Distance across a circle through its centre…represented by “d”

Construct Circles (Unit 8) Student Outcome: I will be able to describe the relationship between radius, diameter and circumference Question… How can you find the diameter if you are given the radius? d = r x 2

Construct Circles (Unit 8) Student Outcome: I will be able to describe the relationship between radius, diameter Question… How can you find the radius if you are given the diameter? r = d ÷ 2

Let’s Construct Circles Can you design the Olympic rings using a compass??

Let’s Construct Circles Can you design the Olympic rings using a compass?? Rubric – Olympic RingsRubric – Olympic rings 5 exact rings/55 exact rings/5 Parallel/2Parallel/2 Straight Lines/3Straight Lines/3 Spacing /Overlap/3Spacing/Overlap/3 Neatness/2Neatness/2 Total/15Total/15

Practice (Homework) Complete questions on pages… Page 271: # 5ab, 6ab, 7ac, 8c, 10, Extend #14, 15

Circumference of a Circle Student outcome: I will be able to describe the relationship of radius, diameter and circumference Circumference: is the distance (perimeter) around a circle. Steps: 1.Wrap a piece of string around the objects circumference 2.Then measure the string along the side of a metre stick. 3.Then measure the diameter of your object and relate it to the circumference. Find The Circumference of Objects!

Circumference of a Circle Student outcome: I will understand radius, diameter, circumference relationships. Circumference: is the distance (perimeter) around a circle. Circular Object CircumferenceDiameterHow many diameters can you fit around the circumference (estimated) Create an equation using “d” Find The Circumference of Objects! What is the relationship between the diameter and circumference of a circle?

Circumference of a Circle Student outcome: I will understand radius, diameter, circumference relationships. Circumference: is the distance (perimeter) around a circle. C = 3 x d (estimated) C = ∏ x d (actual) What is the relationship between the diameter and circumference of a circle? ∏ is very close to 3 (friendly number) The “∏” is known as pi and is known as 3.14

Circumference of a Circle Student outcome: I will understand radius, diameter, circumference relationships Circumference: is the distance (perimeter) around a circle The “∏” is known as pi and is known as 3.14 Diameter Estimated Circumference C= 3 x d Actual Circumference C= ∏ x d

Circumference of a Circle Student outcome: I will understand radius, diameter, circumference relationships Circumference: is the distance (perimeter) around a circle. Diameter Estimated Circumference C= 3 x d

Circumference of a Circle Student outcome: I will understand radius, diameter, circumference relationships Circumference: is the distance (perimeter) around a circle The “∏” is known as pi and is known as 3.14 Diameter Actual Circumference C= ∏ x d

Practical Quiz # The “∏” is known as pi and is known as 3.14 Diameter Estimated Circumference C = 3 x d Actual circumference C = ∏x d

Circumference of a Circle Did you KNOW? The traditional Plains Indian powwow is an annual celebration. People gather together for storytelling, singing, dancing and feasting. The powwow grounds are circles and the performers dance around the circle in a clockwise direction. How would you determine the distance a dancer travels in one complete trip around the circle?

Circumference of a Circle Student outcome: I will understand radius, diameter, circumference relationships PROBLEM: What if you were given the “radius.” Then how would you find the circumference? (Remember...before we multiplied the diameter by 3) 3.14 The “∏” is known as pi and is known as 3.14 Radius (r) r + r = d Estimated Circumference C = 3 x d Actual Circumference C = ∏x d

Practice (Homework) Complete questions on pages… Page : # 3ab, 6, 7ab, 10, 11, 17 (Good Luck) Extend #16, 18, 19

Practical Quiz #2 Using a compass, design a 3 level (snowball) snowman. One snowball has a radius of 2 cm One snowball has a radius of 3 cm One snowball has a diameter of 2 cm

Area means the total amount of space inside of a circle (or any shape). Try to come up with an equation for a circle using the hints given... What are the hints? 5 m Area of a Circle

Area Equation is… Answer is…there are roughly 3 squares (l x w) that fit into a circles. The remaining area outside of the circles roughly make up the area in the 4 th part of the circle. Actual Area Equation: Area = ∏r ² 5 m Area of a Circle

RadiusEstimate Area A = 3 x r x r or A = 3r² Actual Area A = ∏r² or A = ∏ x r x r 6 cm 8 cm 14 cm Area of a Circle Student outcome: I will be able to solve the area of a circle.

Student outcome: I will be able to solve the area of a circle. Area of a Circle Student outcome: I will be able to solve the area of a circle. DiameterFind the “_________” Estimate Area A = 3r² or A = 3xrxr Actual Area A= ∏r² or A = ∏xrxr 6 cm 10 cm 13 cm Show all your work...complete one step at a time!

Practice (Homework) Complete questions on pages… Page : # 4ab, 6, 9ab, 11, 15, 19 (Good Luck!) Extend # 18, 20

Practical Quiz # The “∏” is known as pi and is known as 3.14 Diameter Actual circumference C = ∏x d

Tattoo Me Create a tattoo based on a circle(s)

Tattoo Me Create a tattoo based on a circle(s) RUBRIC Circumference /1 Diameter/1 Radius/1 Area/1 Colored/3 Neatness/3 Originality/3 TOTAL/13

Tattoo Me Create a tattoo based on a circle(s)

Tatoo Me Create art work based on a circle(s)

What is a “Circle Graph” Student outcome: I will be able to read a circle graph. Sector : a section of a circle formed by two radii and the arc of the edge of a circle, which connect the radii Circle Graph: a graph that represents data using sections of a circle 03/Circle_Graph/index.html

Interpret Circle Graphs Student outcome: I will be able to read a circle graph. 1.What is the graph about? 2.What do the different sectors represent? 3.What percent does Mrs. Bosch run? 4.What percent do the kids and Mr. Bosch represent? 5.What do all the sectors add up to be (percent wise)?

Interpret Circle Graphs Student outcome: I will be able to read a circle graph. 1.What is the graph about? 2.What do the different sectors represent? 3.If you have a cat? 4.What are your chances of being a smart kid? 5.What are Mr. Bosch’s chances of being a smart kid?

Practice (Homework) Complete questions on pages… Page : # 3, 5, 7, and 8

Create Circle Graphs Student outcome: I will be able to build a circle graph. You will need… RulerProtractor Compass Pencil Crayons Construct a circle graph with a radius of 8 cm. 1.Create the circle Questions: a)How many degrees are in the top ½ of the circle? b)How many degrees are in the bottom ½ of the circle? c)What is the sum of the central angles of a circle? 8 cm

Create Circle Graphs Student outcome: I will be able to build a circle graph. Complete a Class Survey on Types of Pets! You can only select ONE of the animals mentioned above. Then complete the chart above as a class and work with a partner to create your “Circle Graph.” Favourite House Pet CatDogBirdFishOther Number of Students Fraction Percent Percent of 360°

Create Circle Graphs Student outcome: I will be able to build a circle graph. How do we find the “degrees” of something? % of 360°decimal x 360° Example: 45% x 360° 0.45 x 360° = 162°

Create Circle Graphs Student outcome: I will be able to build a circle graph. Results of Class Survey on Types of Pets! Cat ( %) Dog ( %) Bird ( %) Fish ( %) Other ( %)

Create Circle Graphs Student outcome: I will be able to build a circle graph. Create your OWN survey! (must have 5 choices) Once you’ve completed your data then complete circle graph…make sure to have a LEGEND! Make sure the people you survey only select ONE of the choices! Question Number of Students Fraction Percent Percent of 360°

Unit Review See the “JEOPARDY” game in the Math 7 File… Unit Review Questions: Page : All questions except #10, 22