Lập chương trình nhập vào tọa độ 3 đỉnh A(Xa, Ya), B(Xb, Yb), C(Xc, Yc) của 1 tam giác

uses crt;

var xa,ya,xb,yb,xc,yc:integer;

ab,ac,bc,cv,p,s:real;

begin

clrscr;

write('Nhap toa do diem A:'); readln(xa,ya);

write('Nhap toa do diem B:'); readln(xb,yb);

write('Nhap toa do diem C:'); readln(xc,yc);

ab:=sqrt(sqr(xa-xb)+sqr(ya-yb));

ac:=sqrt(sqr(xa-xc)+sqr(ya-yc));

bc:=sqrt(sqr(xb-xc)+sqr(yb-yc));

if (ab+bc>ac) and (ab+ac>bc) and (ac+bc>ab) then

begin

cv:=ab+bc+ac;

p:=cv/2;

s:=sqrt(p*(p-ab)*(p-ac)*(p-bc));

writeln('Chu vi la: ',cv:4:2);

writeln('Dien tich la: ',dt:4:2);

kt:=0;

if (ab=ac) and (ab<>bc) and (ac<>bc) then kt:=1;

if (ac=bc) and (ac<>ab) and (bc<>ab) then kt:=1;

if (ab=bc) and (ab<>ac) and (bc<>ac) then kt:=1;

if (ab=ac) and (ac=bc) then kt:=2;

if sqr(ab)=sqr(ac)+sqr(bc) then kt:=3;

if sqr(ac)=sqr(ab)+sqr(bc) then kt:=3;

if sqr(bc)=sqr(ab)+sqr(ac) then kt:=3;

if kt=0 then writeln('Day la tam giac thuong');

if kt=1 then writeln('Day la tam giac can');

if kt=2 then writeln('Day la tam giac deu');

if kt=3 then writeln('Day la tam giac vuong');

end

else writeln('Day khong phai la toa do 3 dinh cua mot tam giac');

readln;

end.