Chp 8 Workbook

NAME DATE PERIOD
8-7
Study Guide and Intervention
Vectors
Geometric Vector Operations A vector is a directed segment representing a quantity
that has both magnitude, or length, and direction. For example, the speed and direction of an
airplane can be represented by a vector. In symbols, a vector is written as AB ⎺⎺⎺⎺ , where A is the
initial point and B is the endpoint, or as v . The sum of two vectors is called the resultant.
Subtracting a vector is equivalent to adding its opposite. The resultant of two vectors can be
found using the parallelogram method or the triangle method.
Example
Copy the vectors to find a - b .
Method 1: Use the parallelogram method.
Copy a and - b with the same initial
point.
-b
a
Complete the parallelogram. Draw the diagonal of the
parallelogram from the initial point.
a
a
a
-b
-b -b
a
b
Lesson 8-7
Method 2: Use the triangle method.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Copy a .
a
Exercises
Place the initial point of - b at the
terminal point of a .
Copy the vectors. Then find each sum or difference.
1. c + d
3. a - b
a
-b
a
2. w - z
c d w
b
4. r + t
Draw the vector from the initial
point of a to the terminal point
of - b .
-b
r
z
a - b
t
a
Chapter 8 43 Glencoe Geometry