Circle Commands¶

VektorCAD provides four circle commands accessible from Toolbar > Draw > Circle:

Command	Description
CIRCLE	Create a circle by center point and radius
CIRCLE2P	Create a circle by two diametrically opposite points
CIRCLE3P	Create a circle passing through three points
CIRCLETTR	Create a circle tangent to two entities with a given radius

CIRCLE Command (Center + Radius)¶

Creates a circle by specifying the center point and radius.

Prompts¶

Prompt	Description
Specify center point	Click or type coordinates for the center
Input radius	Type the radius value or click a second point (distance = radius)

Keywords¶

Keyword	Description
CenterMark	Toggle center mark ON/OFF — places a cross-hair point at the center

How to Use¶

Run the CIRCLE command
Optionally type CenterMark to toggle the center mark before placing
Click or type coordinates for the center point
Enter the radius or click a second point — a live preview circle follows the cursor

Command: CIRCLE
Specify center point [CenterMark]: 50,50
Input radius <10>: 25

Tip

The radius value persists across uses of the CIRCLE command. The default starts at 10 units.

CIRCLE2P Command (2-Point Circle)¶

Creates a circle defined by two points that form the diameter.

Prompts¶

Prompt	Description
Specify first point	First endpoint of the diameter
Specify second point	Second endpoint of the diameter

Keywords¶

Keyword	Description
CenterMark	Toggle center mark ON/OFF

How to Use¶

Command: CIRCLE2P
Specify first point [CenterMark]: (click)
Specify second point [CenterMark]: (click)

The circle is created with the center at the midpoint of the two points and the radius equal to half the distance between them. A live preview shows the circle as you move the cursor for the second point.

CIRCLE3P Command (3-Point Circle)¶

Creates a circle passing through three specified points.

Prompts¶

Prompt	Description
Specify first point	First point on the circle
Specify second point	Second point on the circle
Specify third point	Third point on the circle

Keywords¶

Keyword	Description
CenterMark	Toggle center mark ON/OFF

How to Use¶

Command: CIRCLE3P
Specify first point [CenterMark]: (click)
Specify second point [CenterMark]: (click)
Specify third point [CenterMark]: (click)

The unique circle passing through all three points is calculated and created. A live preview updates as you specify the second and third points.

Note

The three points must not be collinear (on the same line). If they are, no circle can be created.

CIRCLETTR Command (Tangent-Tangent-Radius)¶

Creates a circle tangent to two entities with a specified radius.

Prompts¶

Prompt	Description
Select line / Circle / Arc entity (×2)	Pick two entities the circle should be tangent to
Input circle radius	Specify the radius of the new circle
Select circle	If multiple solutions exist, click near the desired one

How to Use¶

Command: CIRCLETTR
Select line / Circle / Arc entity: (pick first entity)
Select line / Circle / Arc entity: (pick second entity)
Input circle radius <10>: 15
Select circle: (click near the desired solution)

The command finds all possible circles of the given radius tangent to both entities and highlights them in different colors. Click near the one you want to create it.

Supported Entity Combinations¶

Entity 1	Entity 2
Line	Line
Line	Circle
Line	Arc
Circle	Circle
Circle	Arc

Center Mark Option¶

All circle commands support the CenterMark keyword. When enabled, a cross-hair point marker is placed at the circle's center after creation. This is useful for:

Dimensioning (radial/diametric dimensions reference the center)
Construction reference points
Visual identification of circle centers

Specify center point [CenterMark]: CenterMark
Turn center mark [ON/OFF] <OFF>: ON
Specify center point [CenterMark]: 50,50
Input radius <10>: 20

Examples¶

Circle at Origin with Radius 30¶

Command: CIRCLE
Specify center point [CenterMark]: 0,0
Input radius <10>: 30

Circle Through Three Bolt Holes¶

Command: CIRCLE3P
Specify first point: (snap to first hole center)
Specify second point: (snap to second hole center)
Specify third point: (snap to third hole center)

Fillet Circle Tangent to Two Lines¶

Command: CIRCLETTR
Select line / Circle / Arc entity: (pick first line)
Select line / Circle / Arc entity: (pick second line)
Input circle radius <10>: 8
Select circle: (click near desired position)

Circle Defined by Diameter¶

Command: CIRCLE2P
Specify first point: 0,0
Specify second point: 100,0

Creates a circle with center at (50, 0) and radius 50.

Best Practices¶

Practice	Benefit
Use Entity Snap for center placement	Precise positioning on existing geometry
Type exact radius for accuracy	Repeatable, dimensionally correct circles
Use CIRCLE3P for circumscribed circles	Pass through known points
Use CIRCLETTR for fillets between entities	Tangent constraint guarantees smooth transitions
Enable CenterMark for dimensioning	Center points ready for radial/diametric dims

Quick Reference¶

Task	Input
Circle by center + radius	`CIRCLE`
Circle by 2 points (diameter)	`CIRCLE2P`
Circle through 3 points	`CIRCLE3P`
Circle tangent to 2 entities	`CIRCLETTR`
Toggle center mark	Type `CenterMark` keyword
Cancel	Escape