The function is defined for all values of x. The domain is ...
... all real numbers.
Add up the lengths of the several sides of the polygon.
Examples: The perimeter of a triangle is the sum of the lengths of the 3 sides.
The perimeter of a hexagon is the sum of the lengths of the 6 sides.
And so on.
I highly recommend drawing any polygon whose perimeter you wish to calculate.
To do this multiply 1 by 4, then 3 by 5. 4 over 15 is your answer.
3 (4x + 6) = 21
4x + 6 = 21/3
4x + 6 = 7
4x = 7 - 6
4x = 1
x = 1/4
