The oscillation period of the mathematical pendulum is 2 s. What will be the period of oscillation

The oscillation period of the mathematical pendulum is 2 s. What will be the period of oscillation of the pendulum if its length is increased by 4 times?

Given:
T = 2 s;
Increase in length by 4 times.
Find: how the period will change.
Decision:
It is important that we can notice that the period of oscillation of the pendulum is proportional to the root of the length of the thread. This conclusion can be drawn from the formula:
T = 2n * root l / g.
That is, it turns out that if the length is increased by 4 times, the period will increase by the root of 4 times. Thus, we get a 2-fold change. This means that the period will no longer be equal to 2s, but twice as long – 4s.
Answer: will increase by 2 times