When the pendulum is moved 28 degrees from the vertical a right triangle is formed where the hypotenuse is 30cm and the side parallel to the vertical is x. If we find x, we can then subtract x from 30cm to find how much the lower end of the pendulum was raised.

First, we find x:

cos(28)=x/30

x=26.49 cm

Therefore, the pendulum is raised:

30-26.49=3.51cm in the vertical direction