Learn/Drafting/Dimensions, Text & Annotation
Dimensions
At a glance
- Linear — click a line or two points; drag to set offset from geometry
- Diameter — click a circle; shows diameter with prefix
- Radius — click an arc; shows radius with R prefix
- Angular — click two lines; measures included angle in degrees
- Point — click any snap point; places X/Y coordinate callout with leader line
- Drag any dimension text to reposition along its line, arc, or leader
One Dimension tool (D) covers every dimension type — what you click decides what you get. Click
a line for its length, a circle for its diameter (prefixed ⌀), an arc for its radius (prefixed
R), two lines for the angle between them, or two points for the distance between them. Click a
snap point on its own and you get an X/Y coordinate callout on a leader. Then move the mouse to
set the offset and click again to place it.
Every dimension drives
Dimensions are parametric from the moment they land: placing one locks the geometry at its current
value without moving anything, and double-clicking the text lets you type a new value — including
math and unit expressions like 1/2in + 3mm (see
Expression Evaluator). The geometry follows. How driving,
reference, and over-constrained dimensions behave is covered in
Constraints & Driving Dimensions.
Placement details worth knowing
- Edge references measure perpendicular. Dimension from a line to a circle's center and you get the true perpendicular distance — two edge-to-center dimensions locate a hole exactly.
- Angular dimensions follow the label. Two lines define four sectors; the dimension measures the one your label sits in, so you can dimension the acute, obtuse, or reflex angle just by where you drop the text.
- Text is always movable. Drag dimension text along its dimension line, arc, or leader at any time — repositioning the label never changes the value or the geometry.
- Values display in your Settings → Preferred Units, inches or millimeters.