This is the first figure given to be drawn. We Take all the lines as given in the figures but we apply Start End Direction Command ARC for 180 first and then a Circle of radius 60 at the center of the figure.
First of all we draw all our lines with their respective measurement. but we now take the exact points from whom the arc should pass and we observe a little different ARC angles this time, the ARC on all sides should be only 20 UNITS on outside and we should get accurate dimension at the end of the figure.
The figures is Shared in the link below.