The solution would be like this for this specific problem:
T = 2 * pi * sqrt (Length / g)
T = 2 * 31.4 * sqrt (1.8m / 3.69 m/second2)
T = 4.386142257432951112677107108824
So
if you had a pendulum on Mars that was 1.8 meters long, the period would be
4.4.