Warm-upMonday, October 26, 2009

Solve each proportion. Round to the nearest tenth where necessary.

a.) b.)

c.) d.) gp

p

f

20

3

16

15

4

9

50

8

3

213

2

6-3 Similar Figures and Scale Drawings

Objectives: You will be able to solve problems that involve similar figures

You will be able to solve problems that involve scale drawings

equalproportion

the same shape, but not necessarily the same size; corresponding angles & sides

using similar figures to compare distances that are difficult to measure directly

an enlarged or reduced drawing that is similar to an actual object or place

similar to; the same shape, but not the same size (necessarily).

Today’s bonus

• Using indirect measurements with shadows, similar figures, and some knowledge of angles, Erotosthenes (276 – 195 BC) calculated the circumference of the Earth with surprising accuracy.

When are we ever going to use this?

• Here are some ideas:– Architecture– Making or using maps– Movie making– Surveying– Manufacturing

Finish the Quick Check before the end of class!

Homework

• Please complete pg. 301 (305) #1-19 ODD

• REMEMBER…– Odd problems have answers in the back of the

book, so you must show your work to receive full credit on your homework!!!

Ticket to Leave

A tree casts a shadow 8 feet long. A 6-ft man casts a shadow 4 ft long. The triangle formed by the tree and its shadow is similar to the triangle formed by the man and his shadow. How tall is the tree?

8

x

4

6