Measuring Geometry

Read distances, angles, areas, coordinates and full object properties with the four Inquiry tools — answers appear in the context bar with a Copy button, and nothing is added to the drawing.

Sometimes you just want to know a number: how far apart those two walls are, how many square metres that room is, what layer this thing is actually on.

Four Inquiry tools answer questions like that. Each shows its answer at the right of the context bar, with a Copy button, until the next command starts. Nothing is drawn, and nothing is changed.

They live in the Inquiry section of the tool palette, and in the Inquiry menu.


Prerequisites

  • Some geometry to measure.

Distance — DI

What it tells you. Pick two points and it reports:

  • the distance between them;
  • the angle from the first to the second;
  • ΔX and ΔY — how far apart they are horizontally and vertically (Δ, "delta", means "the change in").

Turn object snaps on first. Points snap exactly as they do while drawing, so corner-to-corner measuring is as exact as corner-to-corner drawing. Without snaps, you measure from wherever you happened to click. See Precision Object Snaps.

The Distance tool after picking two endpoints, with the context bar showing the distance, angle, delta X and delta Y, and a Copy button at its right

Area — AE

What it tells you. An area and its perimeter. Click round the corners of the region, then press Enter.

OptionKeyWhat it does
ObjectOClick a circle or closed polyline instead of picking corners
AddAKeeps a running total, adding each area you measure
SubtractSKeeps a running total, taking each area away

Add and Subtract are what make this tool genuinely useful. Measure a floor, subtract the stair void and the lift core, and read the net area — all inside one command, finishing with Enter.


List — LI

What it tells you. Every property of the objects you pick: their geometry, layer and style. Use the current selection, or pick objects and press Enter.

You get one line per object. A long list shows its first lines and says how many more there are; Copy takes the lot.

Reach for this when something is behaving oddly and you want to know exactly what it is — whether that "line" is really a polyline segment, which layer it is actually on, what linetype scale it is carrying.


Point Coordinates — ID

What it tells you. A point's X and Y. It snaps just as drawing does.

It reports in the user axes, so it respects any user origin you have set. That means you can read coordinates relative to a setting-out datum on site, rather than relative to the drawing's absolute origin.


Reading values without any tool at all

Two things report continuously, with nothing running:

  • The status bar's coordinate readout gives the cursor's position in the user axes.
  • The Properties panel gives a selected object's derived values: a line's length and angle, a circle's circumference and area, an arc's total angle and arc length, a polyline's vertex count, length and area.

Those panel values are read-only — they are results, not settings. To change a line's length, move its end grip or use Lengthen.

And while a command is running, live measurements appear on the geometry itself — the length and angle of the segment you are drawing — so a good deal of the time you never need to measure at all.


Measuring, or dimensioning?

You wantUse
To read a value now, and not record itAn Inquiry tool
A permanent annotation on the drawingA dimension — see Dimensioning a Drawing

"Measure" is a different command

Confusingly, Draw ▸ Measure (ME) is not one of these tools. It places points at a set spacing along an object — see Divide and Measure.

The tools on this page are all under Inquiry.


Next Steps

Next: Working with Layers