How to use this type coordinate system to solve this question in AutoCAD?

[Xiao16]

[Patchy]

Nobody on earth can help you if you don't attach your .dwg

[Kent1Cooper]

You can use a BOUNDARY or BPOLY command to make a Polyline with the shape of the common area, and then see its area in Properties.

[spear_kevin_pe · Accepted solution]

Surveyors units is an angle setting in the UNITS dialog. Then, enter the bearings and distances as noted. Shaan Hurley writes the AutoCAD blog and detailed this concept there - Drawing with Surveyors Units in AutoCAD (Between the Lines) (blogs.com)

[chadwickt]

In addition to drawing a boundary like Kent suggested, you could also hatch the common area, and find the area of the hatch in the Properties palette.