Parallelogram Rule
Definition Of Parallelogram Rule
Parallelogram Rule provides the means to perform vector addition of two vectors in two-dimensional space.
More About Parallelogram Rule
It is most easily understood in the two-dimensional model.
It is also called parallelogram law.
Examples of Parallelogram Rule
Suppose two persons are pulling a load with a force f1 and f2 in two different directions from a fixed point. Then these forces can be represented as two sides of a parallelogram. By completing the parallelogram and using the parallelogram rule, the diagonal represents the sum of the two original forces f1 + f2.
Video Examples: The Parallelogram Law : Parallelograms & Math
Solved Example on Parallelogram Rule
Ques: Using the Parallelogram rule, find the value of the resultant vector for the given figure.
Choices:
A. 9 cm
B. 20 cm
C. 10 cm
D. 1 cm
Correct Answer: A
Solution:
Step 1: Using the parallelogram rule, if a and b are the vectors that represent the sides of the parallelogram, then the resultant vector is by the diagonal whose value is given as a + b.
Step 2: Then, substituting the values of a and b as 5 cm and 4 cm respectively, the resultant vector is given as (5 + 4) cm = 9 cm.
Step 3: Hence the value of resultant vector is 9 cm.