Construction in GCLC language

dim 120 120

point C 110 40
point O 65 51.14
point T_{a} 70.86 40

color 220 0 0
fontsize 11

cmark_b C
cmark_t O
cmark_b T_{a}
color 0 0 0
fontsize 10

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

color 200 200 200
drawline a
color 0 0 0



% NDG:  points C and O are not the same
% Constructing a circle k(O,C) whose center is at point O and which passes through point C
circle k(O,C) O C 

color 200 200 200
drawcircle k(O,C)
color 0 0 0



% NDG:  line a and circle k(O,C) intersect% DET:  points C and B must be different
% Constructing a point P_{\_G40702} which is a foot of the point O on the line a
foot P_{\_G40702} O a 
cmark_r P_{\_G40702}
color 200 200 200
drawline O P_{\_G40702} 
color 0 0 0

% Constructing a point B which is an image of the point C in the symmetry to point/line P_{\_G40702}
sim B P_{\_G40702} C 
cmark_b B



% Constructing a point M_{a} such that BM_{a}/BC=0.5
towards M_{a} B C 0.5 
cmark_b M_{a}
color 200 200 200
drawsegment B C 
color 0 0 0


% DET:  points O and M_{a} are not the same
% Constructing a line m_{a} which passes through point O and point M_{a}
line m_{a} O M_{a} 

color 200 200 200
drawline m_{a}
color 0 0 0



% NDG:  line m_{a} and circle k(O,C) intersect
% Constructing points N_{a} and N_{ak} which are in intersection of k(O,C) and m_{a}
intersec2 N_{a} N_{ak} k(O,C) m_{a} 
cmark_b N_{a}
cmark_r N_{ak}


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

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



% NDG:  line s_{a} and circle k(O,C) intersect% DET:  points N_{a} and A must be different
% Constructing a point P_{\_G41112} which is a foot of the point O on the line s_{a}
foot P_{\_G41112} O s_{a} 
cmark_r P_{\_G41112}
color 200 200 200
drawline O P_{\_G41112} 
color 0 0 0

% Constructing a point A which is an image of the point N_{a} in the symmetry to point/line P_{\_G41112}
sim A P_{\_G41112} N_{a} 
cmark_t A



drawsegment A B
drawsegment A C
drawsegment B C

% Non-degenerate conditions:  line s_{a} and circle k(O,C) intersect; line m_{a} and circle k(O,C) intersect; line a and circle k(O,C) intersect; points C and O are not the same
% Determination conditions:  points N_{a} and A must be different; points N_{a} and T_{a} are not the same; points O and M_{a} are not the same; points C and B must be different; points C and T_{a} are not the same