how to make a cut

Thanks for the reply Suku. I wanted to know how it is done or using which options in coreldraw I can do that. Also as per the diagram and the formula does it mean that the black coloured curve is of length 2 cm. I have X3 version. Since I am very new in coreldraw I will atleast need to know using what options or functions I can that result. Thanks again.

Regardless of what software you are using, the geometry principles are the same. Fist convert all measurements to a single standard unit, like inches or centimeters. Use those values in the formula to arrive at the required angles. Draw the circle and the lines from the center using the derived angles. Trim off the sections of the circle that are not needed. You are done.