As per the formula of time period of simple pendulum we can say
![T = 2\pi \sqrt{(L)/(g)}](https://img.qammunity.org/2020/formulas/physics/college/ojq1cw3ye86llv5bo4i76xwlp3hm06tv10.png)
so from above formula we can see that time period of pendulum depends on the value of L
so here as we change the length of pendulum the time period will also change
so
Time Period = Dependent Variable
Length = Independent Variable