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.
2.
3.
4.
About 16 in2
About 10 in2
A = (9)(12) = 108 cm2
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 cm
A = πr2 = (3.14)(4)2 =
50.24 cm2
8. d = 2r = 25 mm
r = 12.5 mm
C = 2πr =
2(3.14)(12.5) = 78.5
mm
A = πr2 = (3.14)(12.5)2
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