Polar input in isometric — understanding angles and directions When using Dynamic Input and polar coordinates in AutoCAD isometric drafting, a line drawn from a point “3 inches at 180 degrees” will be oriented in which way?

Introduction / Context:
Even while drawing isometric views, AutoCAD still interprets polar angles in the standard 2D screen coordinate system: 0 degrees to the right, 90 degrees up, 180 degrees to the left, and 270 degrees down. Understanding these conventions helps place edges reliably with Dynamic Input and polar tracking.

Given Data / Assumptions:

• Polar coordinate entry uses standard angles in the current UCS.
• A length of 3 inches is entered with an angle of 180 degrees.
• The question focuses on orientation (horizontal vs. vertical vs. inclined) in screen terms.

Concept / Approach:
In the default UCS, an input of @3<180 means “three units to the left along the X axis,” which is a horizontal direction. Although isometric drawings visually suggest 3D, the drafting process for edges still follows 2D polar angles for cursor direction. Lines along isometric axes are placed by choosing 30-degree increments for left/right axes and 90 degrees for verticals; 180 degrees remains a horizontal direction to the left.

Step-by-Step Solution:

Verification / Alternative check:
Draw a quick test in AutoCAD: @3<180 from any point shows a straight segment leftward, confirming horizontal orientation.

Why Other Options Are Wrong:

• Vertical: would require 90 or 270 degrees.
• Inclined: would require a non-multiple of 90 degrees, e.g., 30 degrees for isometric axes.
• None of the above / perpendicular to XY: not applicable; the line is 2D within the current UCS plane.

Common Pitfalls:

• Mistaking isometric axis angles (30 degrees) for polar absolute directions; the system still interprets polar angles in 2D.

Final Answer:
horizontal