1. Bellwork The Great Pyramid in Egypt, built about 2500 BCE, took approximately 20 years to construct. One estimate of the number of stones—each weighing from two to fifteen tons—is 2.3 million. Assume that the laborers worked 365 days per year for 10 hours a day on average. Estimate the number of stones put in place each hour. The Great Pyramid in Egypt, built about 2500 BCE, took approximately 20 years to construct. One estimate of the number of stones—each weighing from two to fifteen tons—is 2.3 million. Assume that the laborers worked 365 days per year for 10 hours a day on average. Estimate the number of stones put in place each hour. What is the value of a 2 -2ab+b 2, if (a-b)=12 What is the value of a 2 -2ab+b 2, if (a-b)=12 Clickers

2. Bellwork Solution The Great Pyramid in Egypt, built about 2500 BCE, took approximately 20 years to construct. One estimate of the number of stones—each weighing from two to fifteen tons—is 2.3 million. Assume that the laborers worked 365 days per year for 10 hours a day on average. Estimate the number of stones put in place each hour. The Great Pyramid in Egypt, built about 2500 BCE, took approximately 20 years to construct. One estimate of the number of stones—each weighing from two to fifteen tons—is 2.3 million. Assume that the laborers worked 365 days per year for 10 hours a day on average. Estimate the number of stones put in place each hour. Clickers

3. Bellwork Solution What is the value of a 2 -2ab+b 2, if (a-b)=12 What is the value of a 2 -2ab+b 2, if (a-b)=12 Clickers

4. Areas of Circles and Sectors Section 11.5

5. Area of a Circle We’ve already seen the area of a circle, which is given by the formula Theorem 11.9 A=πr 2 r

6. Sectors A sector is a piece of a circle that has a distinct area that can be determined in a similar way to that of arc length r θ This is the amount of the circle that the arc travels through This is the area of circle

7. Sectors What is the area of the sector shown below 15 60

8. On your Own What is the area of the sector shown below 22 110

9. On your own What is the area of the sector shown below 10 200

10. On your own Given the arc lengths, what is the measure of the Area of the sector (shown in green) below? 15 31.42 u 18.33 u

11. Practical Example Pizza from Domino’s comes as a 16” cut into 8 slices. A Extra Large pizza from D’Bronx comes as a 30” pizza cut into 12 slices. What is the ratio of the areas of a Domino’s slice to a D’Bronx slice?

12. On your own What is the area of the shaded space below 3 m 4 m

13. Homework 11.5 2, 15-19, 22, 27-31

14. Homework 11.5 2, 16-19, 22, 28-30 2, 16-19, 22, 28-30