1. LEARNING GOALS – LESSON 7:1 EXAMPLE 1A: WRITING RATIOS
7.1.1: Write and simplify ratios.
7.1.2: Use proportions to solve problems.
A ___________ compares two numbers by division.
Example: ⅗ = ______ = ____ ____ ____
A ___________ can involve more than ____ numbers as well.
Example:
The _________________ cannot equal ____, because it would be _______________.
EXAMPLE 1A: WRITING RATIOS
A. Write a ratio expressing the slope of l.
B. Given that two points on line m are C(–2, 3) and D(6, 5), write a ratio expressing the slope of m.

2. EXAMPLE 1B: USING RATIOS EXAMPLE 2A: SOLVING PROPORTIONS
The ratio of the side lengths of a triangle is 4:7:5, and its perimeter is
96 cm. What is the length of the shortest side?
The ratio of the angle measures in a triangle is 1:6:13. What is the measure of each angle?
A ________________ is an equation stating that two ratios are equal.
Example:
EXAMPLE 2A: SOLVING PROPORTIONS
Solve the proportions. A. B.

3. EXAMPLE 2A (CONT.): SOLVING PROPORTIONS Solve the proportion.
EXAMPLE 2B: USING PROPERTIES OF PROPORTIONS
A. Given that 18c = 24d, find the ratio of d to c in simplest form.
B. Given that 16s = 20t, find the ratio t:s in simplest form.
Example 2C: Application
An apartment building is 90 ft tall and 55 ft wide. If a scale model of this building is 11 in. wide, how tall is the scale model of the building?