# Definition of an exercise ruler & compass.
# syntax of the file.
# points:  each line defines a point.  x,y
# lines:   each line defines two points on a line.   x1,y1,x2,y2,type
#          type: 1 (segment), 2 (line), 3 (semiline direct), 4 (semiline inverse)
#	   type is facultative, defaulting to 1.
# circles: each line defines a circle. x,y,r,n
#	   where (x,y) is the center, r=radius,
#          n is the number of point for the center (if n>0).
# goal: each line defines an object. First item is the type of the object
# (point,line or circle), the rest are parameters (same as above).
# goal_text: text explaining the goal. (language-dependent)

title=Tangent of circle on a point
boundary=circles
c=!random 0,2*pi

points=0,0\
cos($c),sin($c)
circles=0,0,1,1

goal=line,cos($c),sin($c),cos($c)-sin($c),sin($c)+cos($c),2
goal_text=construct the line tangent to circle 1 on point 2
solution=semiline_direct,1,2\
circle,2,1\
point,line,1,circle,2\
circle,1,3\
circle,3,1\
point,circle,3,circle,4\
line,4,5\
hide,circle,4\
hide,circle,3\
hide,point,4\
hide,point,5

