Construction in GCLC language

dim 120 120

point C 110 40
point O 65 51.14
point H_{a} 80 40

color 220 0 0
fontsize 11

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

% DET:  points C and H_{a} are not the same
% Constructing a line a which passes through point C and point H_{a}
line a C H_{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_{\_G31735} which is a foot of the point O on the line a
foot P_{\_G31735} O a 
cmark_r P_{\_G31735}
color 200 200 200
drawline O P_{\_G31735} 
color 0 0 0

% Constructing a point B which is an image of the point C in the symmetry to point/line P_{\_G31735}
sim B P_{\_G31735} C 
cmark_b B



% 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:  line h_{a} and circle k(O,C) intersect
% Constructing points A_{k} and A which are in intersection of k(O,C) and h_{a}
intersec2 A_{k} A k(O,C) h_{a} 
cmark_r A_{k}
cmark_t A



drawsegment A B
drawsegment A C
drawsegment B C

% Non-degenerate conditions:  line h_{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 C and B must be different; points C and H_{a} are not the same