Quadrilateral Review Measure the length and width of

Quadrilateral Review • Measure the length and width of your desktop. • Measure and calculate the distance around the outside of your desktop. • What unit did you use to measure your desks? Why? • What do we call the distance around the outside of an object?

Group Investigation • Get into groups of 4 – Member 1: Task leader-makes sure all students are participating and lets me know if the group needs help or has questions – Member 2: Recorder-keeps group copy of measurements and calculations from activity – Member 3: Measurer-measures items (other members should also check these measurements) – Member 4: Presenter-presents the group’s findings and ideas to the class – Pick your roles now…

Minds On: Measure the distance. around different Object circular Distance objects. Around (cm) Radius (cm) Diameter (cm) BUCKET 54. 5 cm 9. 5 cm 19 cm White board maker Paint 5. 7 cm 0. 7 cm 1. 4 cm 22 cm 3 cm 7 cm Elephant skin ball 55 cm 27. 5 cm 55 cm Stool

Consolidation: What patterns do you see? What do you notice? Perimeter diameter -The distance around circular object is thecircumferenc radius - When you divide c (circumference) by d (diameter), you get a number close to 3. - When you divide the c (circumference) by the r (radius), you get a number close to 6. 2 r = d 6 r=c d=r 3 d = c

• pi = • http: //www. piday. org/million/ is an irrational number • It never repeats • It’s value is • = 3. 14 is a Greek letter

C= xd or C= d d = 41 cm http: //illuminations. nctm. org/Activity. aspx? id=3 547 Circumference, Diameter, and Pi

C= x (r + r) or C = 2 r r= 30 mm Circumference, Pi, and Radius

Solve: C=2 r r= 15 cm

Solve: C=2 r r= 7 cm

Grade 8 Learning Goal: I will calculate the circumference of a circle using the formula we generated as a class. Your job 1. Math Makes Sense Page 245 -246 # 2, 3, 5, 7*, 8, and 9 OR Reflect Due: Monday November 6 th, 2017 2. Coming Soon! Quiz on: -the difference between diameter and radius, calculating circumference