Bài 1:

uses crt;

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

BEGIN

        clrscr;

        write('Nhap do dai canh thu nhat:'); readln(a);

        write('Nhap do dai canh thu hai:'); readln(b);

        write('Nhap do dai canh thu ba:'); readln(c);

        cv:=a+b+c;

        p:=(a+b+c)/2;

        s:=sqrt(p*(p-a)*(p-b)*(p-c));

        writeln('Chu vi:',cv:0:3);

        writeln('Dien tich:',s:0:3);

        if (a=b) or (b=c) or (a=c) then write('D la tam giac can')

        else write('D khong phai tam giac can');

        readln

END.

Bài 2:

uses crt;

var n,i:byte;

a:array[1..100] of word;

BEGIN

        clrscr;

        write('Nhap so luong so:'); readln(n);

        for i:=1 to n do

        begin

                write('Nhap a[',i,']:');

                readln(a[i]);

        end;

        write('Cac so chan la:');

        for i:=1 to n do

                if a[i] mod 2=0 then write(a[i],' ');

        readln

END.

uses crt;
var a,b,c,s,p,cv:real;

begin
clrscr;
write('nhap canh thu nhat:'); readln(a);
write('nhap canh thu hai:'); readln(b);
write('nhap canh thu ba:'); readln(c);
cv:=a+b+c;
p:=(a+b+c)/2;
s:=sqrt(p*(p-a)*(p-b)*(p-c));
writeln('chu vi la: ',cv:1:2);
writeln('dien tich la: ',s:1:2);
if (a=b) or (b=c) or (a=c) then write('tam giac can')
else write('khong phai tam giac can');
readln;
end.

bài 2:

uses crt;

var a: array[1..100] of integer;

     i,n:integer;

begin

clrscr;

write ('nhap so phan tu: ');  readln (n);

for i:=1 to n do

begin

write ('nhap a[',i,']: ');  readln (a[i]);

end;

write ('cac so chan la: '); 

for i:=1 to n do if a[i] mod 2=0 then write (a[i]);

readln;

end;