Looking at the word "linear" notice that it begins with "line."
A linear relationship is a relationship which can be represented by a straight line.
Let's look at an example of a linear relationship.
The perimeter of a square depends on the length of a side.
Perimeter = S + S + S + S = 4s
We can also write this in function notation as P(S) = 4s
Since we have one variable "s" and it's raised to the power of 1, this is a linear relationship.
