Why use the period squared of a pendulum rather than just the period?

Question

Im trying to understand why you use the period squared of a pendulum rather than just the period? and why its useful when drawing a graph? A detailed explanation would be greatly appreciated :")

Answer 1

If you saw my explanation to the problem about the pendulum, I got their the formula for its period.

From this formula we can find g - acceleration due to gravity.

g = 4π² l / T ²

We can experimentally measure the acceleration of free fall g by plotting the graph l vs T². It is the straight line (not a curve!) And the slope of this graph will give us the numerical value of acceleration of gravity (g = 4π²·Slope)