Friday, January 6, 2012 No HW. Study for Ch. 7 on Wed 1/11 Warm Up – Complete #20 on back of HW – “An architect …”

Friday, January 6, 2012

• No HW. • Study for Ch. 7 on Wed 1/11• Warm Up –

Complete #20 on back of HW – “An architect …”

An architect …

Agenda

• Review of Area of Irregular Figures• Review Study Guide• Practice with finding area

Area of Irregular Figures

• Don’t assume anything!

Study Guide

1. About 16 in2

2. About 10 in2

3. A = (9)(12) = 108 cm2

4. A = ½ (16)(24) = 192 in2

5. A = ½ (7.5)(5+10) = 56.25 m2

6. A = triangle + square= ½ (8)(12) + (12)2

= 48 + 144 = 192 cm2

Study Guide

7. C = 2πr = 2(3.14)(4) = 25.12 cmA = πr2 = (3.14)(4)2 = 50.24 cm2

8. d = 2r = 25 mmr = 12.5 mmC = 2πr = 2(3.14)(12.5) = 78.5 mmA = πr2 = (3.14)(12.5)2 = 490.625 mm2

Cold Call!

How do you find the area?Keep your study guide out!

What is pi (π)?

Additional Practice

• What did the scientist say to the hydrogen atom that claimed to have lost an electron?

• What happened when the TV set asked the remote control for a date?

• Answers will be posted at www.teachervivian.com