EXAMPLE 3 Draw a perpendicular line Line h

EXAMPLE 3 Draw a perpendicular line Line h passes through (3, 0) and (7, 6). Graph the line perpendicular to h that passes through the point (2, 5). SOLUTION STEP 1 Find the slope m 1 of line h through (3, 0) and (7, 6). m 1 = 6 – 0 = 6 = 3 7– 3 4 2

EXAMPLE 3 Draw a perpendicular line STEP 2 Find the slope m 2 of a line perpendicular to h. Use the fact that the product of the slopes of two perpendicular lines is – 1. 3 2 m 2 = – 1 m 2 = – 2 3 STEP 3 Slopes of perpendicular lines Multiply each side by 2 3 Use the rise and run to graph the line.

EXAMPLE 4 Standardized Test Practice SOLUTION The rate at which the skydiver descended is represented by the slope of the segments. The segments that have the same slope are a and c. ANSWER The correct answer is D.

for Examples 3 and 4 GUIDED PRACTICE 4. Line n passes through (0, 2) and (6, 5). Line m passes through (2, 4) and (4, 0). Is n m? Explain. SOLUTION Find the slope of line n through (0, 2) and (6, 5). n = 2– 5 0– 6 = – 3 – 6 = 1 2

for Examples 3 and 4 GUIDED PRACTICE Find the slope of line m through (2, 4) and (4, 0). m = 4– 0 = 4 – 2 2– 4 = – 2. Find the product. n m = 1 2 – 2 = – 1. Since the product of the slopes of line n and m is – 1. Hence , they are perpendicular to each other.

GUIDED PRACTICE 5. for Examples 3 and 4 In Example 4, which parachute is in the air for the longest time? Explain. ANSWER Parachute C is in air for longest times. It in the air approximately 1. 25 minutes longer than either a or b.

GUIDED PRACTICE 6. for Examples 3 and 4 In Example 4, what do the x-intercepts represent in the situation? How can you use this to eliminate one of the choices? ANSWER The x- intercepts represent time of the landing in the situation. b and c are in the air different amounts of time, so we can eliminate choice b.