Line/Parlel,Tanto,C
Parallel to Line and Tangent to Circle
Creates a line parallel to an existing line and tangent to a circle. Direction selector required.
What It Does
The Line/Parlel,Tanto,C operator creates a line that is simultaneously parallel to an existing line and tangent to a circle. Two solutions exist — one on each side of the circle. The direction selector specifies which one.
Syntax
Line/L1, Parlel, Tanto, C1, XLarge|XSmall|YLarge|YSmall
Quick Input
L: [reference line — parallel to this]
C: [circle — tangent to this]
Dir: ○ XL ○ XS ● YL ○ YS
Direction Selector
| Selector | Picks |
|---|---|
YLarge | Upper parallel tangent line (for horizontal reference) |
YSmall | Lower parallel tangent line (for horizontal reference) |
XLarge | Right parallel tangent line (for vertical reference) |
XSmall | Left parallel tangent line (for vertical reference) |
Worked Examples
Setup:
L0 = Horizontal line at Y=0
C0 = Centre (50,40), radius 20
Parallel to L0 = horizontal lines
Tangent to C0: Y = 40-20=20 or Y = 40+20=60
Line/L0, Parlel, Tanto, C0, YSmall
→ L1: horizontal line Y=20 (lower tangent)
Line/L0, Parlel, Tanto, C0, YLarge
→ L2: horizontal line Y=60 (upper tangent)
Analytic Rule
Parallel to L constrains direction (same slope).
Tangent to C constrains offset distance.
Offset line parallel to L at distance = circle radius
from circle centre. Two solutions — one each side.
Result: Exact analytic parallel tangent line.
FAQ
When would I use this operator?
Common use: creating a tangent line parallel to a known reference — for example, a tangent to a boss circle parallel to a datum edge.
What if the circle is very far from the reference line?
The operator works regardless of the distance between L and C. The tangent line is always at distance r from the circle centre, parallel to L.