Trigonometric Exercise 1

Hi

I start learning trigo,

My program should do a simple thing,

1. User press p1, than p2 (vertically up to down)
   
2. A line will be drawn , composing segment a
   
3. User press p3(horizontally, forming the base)
   
4. segment c (hyp) distance and angle will take place
   
5. A line will be drawn composing segment c
   

Final output is not correct

Any idea why?

(defun finding-c(/ p1 p2 p3 dst segC isegC)
 (setq p1 (getpoint "\nSpecify first point"))
 (setq p2 (getpoint p1 "\nSpecify second point"))
 (command "_pline" p1 p2 "")
 
 (setq p3 (getpoint p2 "\nSpecify third point"))
 (command "_pline" p2 p3 "")


;;; get the length of the missing segment
 (setq dst (sqrt
      (+
	(* (distance  p1 p2) (distance  p1 p2)) ;power 2
	(* (distance  p2 p3) (distance  p2 p3)) ;power 2
      )
    )
)

 

 ;;; get the angle of the missing segment

 (setq raw (/ (distance  p2 p3) (distance  p1 p2)));;; get tanges
 

(setq p4 (polar p3 (atan raw)  dst))
 (command "_pline" p3 p4 "")
 
 
 )

Final output is not correct

Any idea why?

The angle that you are calculating is interior angle of the triangle, whereas the angle supplied to the polar function is measured from the x-axis.

Samifox Why not just draw 1 pline ? rather than 3 or do you want all 3 ? You can still do angles etc

(setq p1 (getpoint "\nSpecify first point"))
 (setq p2 (getpoint p1 "\nSpecify second point"))
 (setq p3 (getpoint p2 "\nSpecify third point"))
 (command "_pline" P1 p2 p3 "C" )

hi

as far as i understand ,

(polar (start in p3) (orient 27 degrees) (shoot 11.18 length))

isnt that right?

(see attachment)