Ratio, Proportion and Similarity

1
Ratio, Proportion and Similarity

• 10.1

2
Definitions

• Proportion-
• Extended Proportion-
• Cross product-
• Scale drawing-
• Scale-
• Golden rectangle-
• Golden ratio-

3
Properties of Proportions

• a/b c/d is equivalent to
• 1) ad bc
• 2) b/a d/c
• 3) a/c b/d
• 4) (ab)/b (cd)/d

4
Similarity in Shapes

• Similar?

4
3
3
3
2
2
3
4
3
4
2
3
No, 2/3 3/4
5
Similarity in Shapes

• Similar?

8
6
4
3
Yes, ¾ 6/8
6
Homework

• P. 499 1-26, 30-33