ACAD's plane coordinates and spatial coordinates (including polar coordinates) are mathematical Cartesian coordinates.

But building coordinates are different from design coordinates and mathematical coordinates.

The x axis of the building coordinates is the north-south direction, the y axis is the east-west direction, and the azimuth angle is positive clockwise from the north. The origin 0,0 is stipulated by the state.

The A axis of the design coordinate is the vertical direction of the drawing, the B axis is the horizontal direction, and the angle is clockwise when viewed from above the A axis ... The coordinate origin is specified by the design department and given on the ground and drawings.

When the world coordinates of ACAD are used as architectural coordinates, only XY? Just use it backwards.