Construction in GCLC language

dim 120 120

point B 20 40
point H_{a} 80 40
point T_{b} 94.25 68.88

color 220 0 0
fontsize 11

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

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

color 200 200 200
drawline a
color 0 0 0




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

color 200 200 200
drawline h_{a}
color 0 0 0



% NDG:  point T_{b} is not incident to the line a
% Constructing a point P_{\_G28419} which is a foot of the point T_{b} on the line a
foot P_{\_G28419} T_{b} a 
cmark_r P_{\_G28419}
color 200 200 200
drawline T_{b} P_{\_G28419} 
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_{\_G28419}
circle k(T_{b},foot[T_{b},c]) T_{b} P_{\_G28419} 

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_{\_G28810} which is a foot of the point T_{b} on the line a
foot P_{\_G28810} T_{b} a 
cmark_r P_{\_G28810}
color 200 200 200
drawline T_{b} P_{\_G28810} 
color 0 0 0

% Constructing a line L_{\_G28813} which passes through point T_{b} and point B
line L_{\_G28813} T_{b} B 

color 200 200 200
drawline L_{\_G28813}
color 0 0 0


% Constructing a point P_{\_G28816} which is an image of the point P_{\_G28810} in the symmetry to point/line L_{\_G28813}
sim P_{\_G28816} L_{\_G28813} P_{\_G28810} 
cmark_r P_{\_G28816}

% Constructing a line c which passes through point B and point P_{\_G28816}
line c B P_{\_G28816} 

color 200 200 200
drawline c
color 0 0 0



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


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

color 200 200 200
drawline b
color 0 0 0



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



drawsegment A B
drawsegment A C
drawsegment B C

% Non-degenerate conditions:  lines a and b are not parallel; lines c and h_{a} 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 a
% Determination conditions:  lines a and b are not the same; points T_{b} and A are not the same; lines c and h_{a} are not the same; points B and H_{a} are not the same