Construction in GCLC language

dim 120 120

point B 20 40
point T_{a} 70.86 40
point I 74.37 61.15

color 220 0 0
fontsize 11

cmark_b B
cmark_b T_{a}
cmark_b I
color 0 0 0
fontsize 10

% DET:  points B and T_{a} are not the same
% Constructing a line a which passes through point B and point T_{a}
line a B T_{a} 

color 200 200 200
drawline a
color 0 0 0



% DET:  points T_{a} and I are not the same
% Constructing a line s_{a} which passes through point T_{a} and point I
line s_{a} T_{a} I 

color 200 200 200
drawline s_{a}
color 0 0 0



% NDG:  point I is not incident to the line a
% Constructing a point P_{\_G39407} which is a foot of the point I on the line a
foot P_{\_G39407} I a 
cmark_r P_{\_G39407}
color 200 200 200
drawline I P_{\_G39407} 
color 0 0 0

% Constructing a circle k(I,P_{a}) whose center is at point I and which passes through point P_{\_G39407}
circle k(I,P_{a}) I P_{\_G39407} 

color 200 200 200
drawcircle k(I,P_{a})
color 0 0 0



% NDG:  point B is outside the circle k(I,P_{a})
% Constructing a point P_{\_G39614} which is a foot of the point I on the line a
foot P_{\_G39614} I a 
cmark_r P_{\_G39614}
color 200 200 200
drawline I P_{\_G39614} 
color 0 0 0

% Constructing a line L_{\_G39617} which passes through point I and point B
line L_{\_G39617} I B 

color 200 200 200
drawline L_{\_G39617}
color 0 0 0


% Constructing a point P_{\_G39620} which is an image of the point P_{\_G39614} in the symmetry to point/line L_{\_G39617}
sim P_{\_G39620} L_{\_G39617} P_{\_G39614} 
cmark_r P_{\_G39620}

% Constructing a line c which passes through point B and point P_{\_G39620}
line c B P_{\_G39620} 

color 200 200 200
drawline c
color 0 0 0



% NDG:  lines c and s_{a} are not parallel% DET:  lines c and s_{a} are not the same
% Constructing a point A which belongs to line c and line s_{a}
intersec A c s_{a} 
cmark_t A


% NDG:  point A is outside the circle k(I,P_{a})
% Constructing a point P_{\_G40006} which is a foot of the point I on the line c
foot P_{\_G40006} I c 
cmark_r P_{\_G40006}
color 200 200 200
drawline I P_{\_G40006} 
color 0 0 0

% Constructing a line L_{\_G40009} which passes through point I and point A
line L_{\_G40009} I A 

color 200 200 200
drawline L_{\_G40009}
color 0 0 0


% Constructing a point P_{\_G40012} which is an image of the point P_{\_G40006} in the symmetry to point/line L_{\_G40009}
sim P_{\_G40012} L_{\_G40009} P_{\_G40006} 
cmark_r P_{\_G40012}

% Constructing a line b which passes through point A and point P_{\_G40012}
line b A P_{\_G40012} 

color 200 200 200
drawline b
color 0 0 0



% NDG:  lines b and a are not parallel% DET:  lines b and a are not the same
% Constructing a point C which belongs to line b and line a
intersec C b a 
cmark_b C



drawsegment A B
drawsegment A C
drawsegment B C

% Non-degenerate conditions:  lines b and a are not parallel; point A is outside the circle k(I,P_{a}); lines c and s_{a} are not parallel; point B is outside the circle k(I,P_{a}); point I is not incident to the line a
% Determination conditions:  lines b and a are not the same; lines c and s_{a} are not the same; points T_{a} and I are not the same; points B and T_{a} are not the same