Formula to find the area of the sector is:
Where r= radius and \theta= central angle.
Given, radius is 4 centimeters has a central angle of 30'.
So, we can plug in r=4 and \theta=30° in the above formula to get the area of circle. So,

A= 16*15
A= 240
So, the area of sector is 240 square centimeters.