*Tính diện tích tam giác với 3 cạnh

program dientich;

uses crt;

var a,b,c,p,s:real;

begin

clrscr;

write('Nhap a: ');   readln(a);

write('Nhap b: ');   readln(b);

write('Nhap c: ');   readln(c);

p:=(a+b+c)*0.5;

s:=sqrt(p*(p-a)*(p-b)*(p-c));

writeln('Dien tich tam giac la: ',s:2:2);

if s>50 then write('Lon hon dien tich hinh chu nhat')

else if s=50 then write('Bang dien tich hinh chu nhat')

     else if s<50 then write('Nho hon dien tich hinh chu nhat');

readln

end.

*Tính diện tích bằng đường cao

program dientichl

uses crt;

var a,h,s:real;

begin

clrscr;

write('Nhap canh day: ');   readln(a);

write('Nhap duong cao: ');   readln(h);

s:=a*h*0.5;

writeln('Dien tich tam giac la: ',s:2:0);

if s>50 then write('Lon hon dien tich hinh chu nhat')

else if s=50 then write('Bang dien tich hinh chu nhat')

     else if s<50 then write('Nho hon dien tich hinh chu nhat');

readln

end.

uses crt;

var a,h,s: real;

begin

clrscr;

write ('nhap canh day: ');  readln (a):

write ('nhap chieu cao: ');  readln (h);

s:=a*h/2;

writeln ('dien tich la: ',s); 

if s>50 then writeln ('dien tich tam giac lon hon dien tich hinh chu nhat');

if s<50 then writeln ('dien tich tam giac nho hon dien tich hinh chu nhat');

if s=50 then writeln ('dien tich tam giac bang dien tich hinh chu nhat');

readln;

end.