1. Warm-ups - Chapter 5 01/12 page 168 #3-8 all (CE)

2. Section 7-1
Ratio & Proportion

3. ratio quotient proportion
The _______ of one number to another number is the __________ when the 1st number is divided by the second number. A ____________ is an equation stating that two ratios are equal. For example, 𝑎 𝑏 = 𝑐 𝑑 and a:b = c:d are equivalent forms of the same proportion. Either form can be read “a is to b as c is to d.” The number a is called the first term of the proportion. The numbers b, c, and d are the second, third, and fourth terms, respectively.
quotient
proportion

4. Extremes: ______________________________ Means: _________________________________ Means – Extremes Property: _____________________________________________________________
first and last terms
middle terms
the product of the extremes equals
the product of the means

5. Examples: 1. The ratio of 6 to 18 is _____ = _____. 2
Examples: 1. The ratio of 6 to 18 is _____ = _____. 2. The ratio of 30 to 24 is _____ = _____. 3. The extended ratio 10 : 5 : 60 = __________.
6 18
1 3
30 24
5 4
2 : 1 : 12

6. 4. Find the following ratios. a. AD to BC _________________ b
4. Find the following ratios. a. AD to BC _________________ b. mA to mD _________________ c. mD to mC _________________
10x to 8 →
5x to 4
50 to 130 →
5 to 13
130 to 90 →
13 to 9

7. 5. A poster is 1 m long and 52 cm wide
5. A poster is 1 m long and 52 cm wide. Find the ratio of the width to the length.
6. A mirror is 2 ft wide and 34 in long. Find the ratio of the width to the length.
52 𝑐𝑚 1 𝑚 =
52 𝑐𝑚 100 𝑐𝑚 =
13 𝑐𝑚 25 𝑐𝑚
2 𝑓𝑡 34 𝑖𝑛 =
24 𝑖𝑛 34 𝑖𝑛 =
12 𝑖𝑛 17 𝑖𝑛

8. = 𝑥 = 12 𝑥 𝑥 10 = 10 25
2x = 16
3x = 60
25x = 100
x = 20
x = 4
x = 8

9. 10. The measures of 3 angles of a triangle are in the ratio of 2 : 2 : 5. Find the measure of each angle.
11. The measures of 3 angles of a triangle are in the ratio of 3 : 4 : 11. Find the measure of each angle.
2x + 2x + 5x = 180
9x = 180
x = 20
40°, 40°, 100°
3x + 4x + 11x = 180
18x = 180
x = 10
30°, 40°, 110°

10. 12. The ratio of 2 complementary angles is 1 : 2. Find the angles. 13
12. The ratio of 2 complementary angles is 1 : 2. Find the angles. 13. The ratio of 2 supplementary angles is 2 : 7. Find the angles.
x + 2x = 90
3x = 90
30° and 60°
x = 30
2x + 7x = 180
9x = 180
x = 20
40° and 140°

11. 14. The measures of the angles of a quadrilateral are in the ratio of 7 : 8 : 9 : 12. Find the angles.
(n – 2) 180
7x + 8x + 9x + 12x = 360
36x = 360
x = 10
70°, 80°, 90° and 120°

12. In the figure, 𝐴𝐷 𝐷𝐵 = 𝐶𝐸 𝐸𝐵. 15
In the figure, 𝐴𝐷 𝐷𝐵 = 𝐶𝐸 𝐸𝐵 If CE = 2, EB = 6, and AD = 3, then DB = _____. 16. If AB = 10, DB = 8, and CB = 7.5, then EB = ____. 2 10 9
3 𝐷𝐵 = 2 6
2DB = 18 8
DB = 9 x 6
7.5 – x
2x = 60 – 8x
7.5
2 8 = 7.5−𝑥 𝑥
10x = 60
x = 6

13. HOMEWORK: Page 243 #2-30 even WRITTEN EXERCISES Bottom of Page