Bell work Find your name that is your
Bell work: Find your name; that is your new seat. Say hi to your face partner(sitting across from you) and your shoulder partner(sitting next to you)
Today’s Goal(s) Solve Problems involving Proportions Identify shapes Similarity in different
7. 1: Ratios and Proportions
If a baseball team had the following win-loss record for the years shown, which year(s) were they most successful?
Ratios
The Bonsai Bald Cypress tree is a miniature version of a full sized tree. They measure 15 inches tall. There is a Florida Bald Cypress tree named the Senator which stands 118 FEET tall. What is the ratio of the height of a Bonsai to the Senator?
With your shoulder partner
Using extended ratios What is the extended ratio we can write? If the perimeter of the triangle is 98, what would the length of the longest side be? Compare your answer with your face partner when finished.
Magic 11 Each member of your group acts as if they are playing rock, paper, scissors. However, instead of playing one of those, they will hold out a number 0 through 5. The goal of the game is to get the sum of your whole group’s fingers to equal 11. Keep playing until you get it! Once you hit that target, someone in your group picks a new number. Repeat.
Notes An equation involving ratios is called a proportion. The first and last numbers in the proportion are known as extremes, whereas the middle numbers are called the means. i. e. , 2: 3=4: 6 is a proportion. 2 and 6 are the extremes, and 3 and 4 are the means. Just like with ratios, we can have an extended proportion, such as 2: 3=4: 6=8: 12 Cross Product Property: In a proportion, the product of the means equals the product of the extremes. i. e. , 2 x 6 should be equal to 3 x 4
More Notes
In this picture, x: 6 = y: 7. Therefore, x: y would equal…what?
Break Time
7. 2: Similar Polygons
Similar Figures are figures which have the exact same shape, but not necessarily the same size. This is shown with the symbol ~ All the corresponding sides will be in the same ratio, as shown above. The simplified form of this ratio is called the scale factor, and we could say the scale factor of ABCD to GHIJ is AB: GH, or BC: HI, etc.
MNP ~ SRT What are the pairs of congruent angles? What is the extended proportion of the side ratios?
Is JKLM ~ TUVW? If so, find the scale factor
Is ABC ~ EFD? If so, find the scale factor
Are these two shapes similar?
Homework: Section 7. 1, page 436: 9 -12, 16, 17, 19, 23, 24 Section 7. 2, pages 444 -445: 9, 10, 12, 13, 17
Section 7. 1, page 436
Section 7. 2 Pages 444 -445
- Slides: 24