Routine in order to obtain angles

Hello,
I need somebodies help please.
I want a routine that increments 0.05 degrees, each time, starting on 0.05, with a maximum value of 2PI , until we reach the closest value to Q2, wich is a variable that we already know its value.
After reaching this value, I need the routine to give me the required value.
The attached file is an arcaic manner of calculating the q(angle), the Q2 in highlighted in blue, the closest value is in green and the required value is in yellow.
With this value I will be able to calculate the velocity of the flow rate of liquids.
Thank you