In this lesson, students apply theorems about circles to solve problems.
First, they use sector area and radian measurements to analyze the value of several pizza slice deals. In this activity, students have the opportunity to use appropriate tools strategically (MP5) when they decide whether to use protractors or string and ruler to approximate angle measures, and consider the use of spreadsheets and calculators.
Two optional activities follow. In the first, students continue their exploration of sector area, combining it with trigonometry to analyze areas of sectors that have an isosceles triangle at the central angle removed. In the second, students apply properties of inscribed angles and circumscribed circles to a situational context.
Lesson overview
- 14.1 Warm-up: Equal Slices (5 minutes)
- 14.2 Activity: Pizza Palooza (25 minutes)
- 14.3 Optional Activity: A Fair Split (15 minutes)
- 14.4 Optional Activity: Let Your Light Shine (15 minutes)
- Lesson Synthesis
Learning goals:
- Use properties of circles to solve geometry problems arising from situations.
Learning goals (student facing):
- Let’s use geometry to solve problems.
Learning targets (student facing):
- I can use properties of circles to solve geometric problems.
Required materials:
- Geometry toolkits
- Pre-printed slips, cut from copies of the blackline master
- Protractors
- Rulers
- Scientific calculators
- Spreadsheet technology
- String
Standards:
- This lesson builds towards the standard:CCSS.HSG-MG.A.3MS.G-MG.3MO.G.MG.A.3
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