Parallel & Perpendicular Lines Worksheet (Page 3 of 4) in pdf

Parallel & Perpendicular Lines Worksheet Page 3

Writing Equations of Parallel and Perpendicular Lines

1. Identify the slope of the given equation.

2. Decide if you need a parallel (same slope) or perpendicular (opposite reciprocal slope) line.

3. Identify the slope and point of the line you will be using to write the equation of the line.

4. Substitute the slope and the point into point-slope form.

5. Rewrite your answer in slope-intercept form.

Example 1 – Write an equation of a parallel line.

Find the equation of a line that contains the point (-3, 5) and is parallel to the line y = 3x – 1.

Step 1: Identify the slope of the given line.

* Remember: the equation MUST be in slope-intercept form first in order to tell slope

Step 2: Decide if you need a parallel or perpendicular slope.

* Since we are asked for a parallel line, we need the ____________ slope.

Step 3: Identify the slope and the point you will be using to write the new equation.

slope: _____

point: _______

Step 4: Substitute the slope and the point into point-slope form:

Step 5: Rewrite in slope-intercept form.

Your Turn

Write an equation in both point-slope form and slope-intercept form of the line that passes

through the given point and is parallel to the given line.

1. passes through (-2, 11), parallel to y = -x + 5

2. passes through (4, 2), parallel to 2x + y = 4

Point-slope: _____________________

Slope-intercept: __________________

Parallel & Perpendicular Lines Worksheet Page 3