1. 0 Did you find this post helpful? Yes

## Draw arc

Hi

i have problem drawing arc.
scenario is :
user select line and my routine will draw arc. Line is tangent to arc.
Problem si how autocad declare start and end angle of the arc.

2. 0 Did you find this post helpful? Yes

## Re: Draw arc

(defun c:tn ( / ed ent po oldlay )

(while(setq ent (car(setq po(entsel "\nSelect an ARC/LINE"))))
(setq ed (entget ent))
(cond
((= (dxf 0 ed)"ARC")
(tnLine ent po)
)
((= (dxf 0 ed)"LINE")
(setq p1 (dxf 10 ed) p2(dxf 11 ed))
(if (equal po p1 0.001)
(command "LINE" p2 p1 "")
(command "LINE" p1 p2 "")
)
(entdel (entlast))
(setq oldlay (getvar "CLAYER"))
(command "ARC" "" pause)
(command "MATCHPROP" ent (entlast)"")
)
)
)

)

;;
;; Draw tangent line
;;

(defun tnLine ( ent po / obj poFrom ang StartP oldlay)
(setq oldlay (getvar "CLAYER"))
(setq obj (vlax-ename->vla-object ent ))
(setq StartP nil)
(if (not(equal (setq poFrom (vlax-safearray->list (vlax-variant-value (vlax-get-property obj 'StartPoint)))) po 0.0001))
(setq poFrom (vlax-safearray->list (vlax-variant-value (vlax-get-property obj 'EndPoint))))
(setq StartP T)
)
(if StartP
(setq ang (-(vlax-get-property obj 'StartAngle)(/ pi 2)))
(setq ang (+ (vlax-get-property obj 'EndAngle)(/ pi 2)))
)
(command "_.LINE" poFrom (polar poFrom ang (getdist poFrom "\nDistance:"))"")
(command "MATCHPROP" ent (entlast)"")

)

3. 0 Did you find this post helpful? Yes

## Re: Draw arc

Originally Posted by krkeec763189
Hi

i have problem drawing arc.
scenario is :
user select line and my routine will draw arc. Line is tangent to arc.
Problem si how autocad declare start and end angle of the arc.