Construction in GCLC language

dim 120 120

point B 20 40
point H_{c} 68.91 84.83
point T_{b} 94.25 68.88

color 220 0 0
fontsize 11

cmark_b B
cmark_lt H_{c}
cmark_rt T_{b}
color 0 0 0
fontsize 10

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

color 200 200 200
drawline c
color 0 0 0




% Constructing a line h_{c} which is perpendicular to line c and which passes through point H_{c}
perp h_{c} H_{c} c 

color 200 200 200
drawline h_{c}
color 0 0 0



% NDG:  point T_{b} is not incident to the line c
% Constructing a point P_{\_G51173} which is a foot of the point T_{b} on the line c
foot P_{\_G51173} T_{b} c 
cmark_r P_{\_G51173}
color 200 200 200
drawline T_{b} P_{\_G51173} 
color 0 0 0

% Constructing a circle k(T_{b},foot[T_{b},c]) whose center is at point T_{b} and which passes through point P_{\_G51173}
circle k(T_{b},foot[T_{b},c]) T_{b} P_{\_G51173} 

color 200 200 200
drawcircle k(T_{b},foot[T_{b},c])
color 0 0 0



% NDG:  point B is outside the circle k(T_{b},foot[T_{b},c])
% Constructing a point P_{\_G51564} which is a foot of the point T_{b} on the line c
foot P_{\_G51564} T_{b} c 
cmark_r P_{\_G51564}
color 200 200 200
drawline T_{b} P_{\_G51564} 
color 0 0 0

% Constructing a line L_{\_G51567} which passes through point T_{b} and point B
line L_{\_G51567} T_{b} B 

color 200 200 200
drawline L_{\_G51567}
color 0 0 0


% Constructing a point P_{\_G51570} which is an image of the point P_{\_G51564} in the symmetry to point/line L_{\_G51567}
sim P_{\_G51570} L_{\_G51567} P_{\_G51564} 
cmark_r P_{\_G51570}

% Constructing a line a which passes through point B and point P_{\_G51570}
line a B P_{\_G51570} 

color 200 200 200
drawline a
color 0 0 0



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


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

color 200 200 200
drawline b
color 0 0 0



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



drawsegment A B
drawsegment A C
drawsegment B C

% Non-degenerate conditions:  lines c and b are not parallel; lines a and h_{c} are not parallel; point B is outside the circle k(T_{b},foot[T_{b},c]); point T_{b} is not incident to the line c
% Determination conditions:  lines c and b are not the same; points T_{b} and C are not the same; lines a and h_{c} are not the same; points B and H_{c} are not the same