a = float(input("Nhap a : "))
b = float(input("Nhap b : "))
c = float(input("Nhap c : "))
if a+b>c and a+c>b and b+c>a:
    if a==b or a==c or b==c:
        if a==c==b:
            print("Day la ba canh cua tam giac deu")
        else:
            print("Day la ba canh cua tam giac can")
    elif (a**2)+(b**2)==c**2 or (a**2)+(c**2)==b**2 or (c**2)+(b**2)==a**2:
        print("Day la ba canh cua tam giac vuong")
    else:
        pass
else:
    print("Day khong phai ba canh cua tam giac")

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

begin

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

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

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

if (a+b>c) and (b+c>a) and (c+a>b) then 

begin

p:=(a+b+c)/2;

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

writeln('Chu vi tam giac la ',2*p:5:2, '(dvdd)');

writeln('Dien tich tam giac la: ',s:5:2, '(dvdt)');

if (a=b) and (b=c) then writeln('Day con la tam giac deu') else

if (a=b) or (b=c) or (c=a) then writeln('Day la tam giac can') else

if (a*a+b*b=c*c) or (b*b+c*c=a*a) or (c*c+a*a=b*b) then writeln('Day la tam giac vuong') else

writeln('Day la tam giac thuong');

if ((a=b) or (b=c) or (c=a)) and ((a*a+b*b=c*c) or (b*b+c*c=a*a) or (c*c+a*a=b*b)) then writeln('Day la tam giac vuong can')

end

else writeln(a:5:2,',',b:5:2,',',c:5:2,' khong la do dai mot tam giac');

end.

help me !!!!!!

èo lớp 8 khó thế:v

sao ko tham khảo 

=V lúc trước làm bài này nhưng quên cách làm rồi

uses crt;

var a,b,c:real;

begin

clrscr;

repeat

write('Nhap a='); readln(a);

write('Nhap b='); readln(b);

write('Nhap c='); readln(c);

until (a>0) and (b>0) and (c>0);

if (a+b>c) and (a+c>b) and (b+c>a) then 

begin

writeln('La do dai ba canh cua tam giac');

writeln('Chu vi tam giac la: ',a+b+c:4:2);

end

else writeln('Khong phai la do dai 3 canh cua tam giac');

readln;

end.

#include <bits/stdc++.h>

using namespace std;

double a,b,c;

int main()

{

cin>>a>>b>>c;

if (a>0 && b>0 && c>0 && a+b>c && a+c>b &&b+c>a) cout<<"phai";

else cout<<"ko phai";

return 0;

}

#include <bits/stdc++.h>

using namespace std;

double a,b,c;

int main()

{

cin>>a>>b>>c;

if (a>0 && b>0 && c>0 && a+b>c && a+c>b &&b+c>a) cout<<"phai";

else cout<<"ko phai";

return 0;

}

#include <iostream>
using namespace std;
int main()
{
    int a,b,c,kt;
    cout<<"Nhap a=";
    cin>>a;
    cout<<"Nhap b=";
    cin>>b;
    cout<<"Nhap c=";
    cin>>c;
    if ((a>0) and (b>0) and (c>0) and (a+b>c) and (a+c>b) and (b+c>a))
    {
        kt=0;
        if (a*a==b*b+c*c) kt=1;
        if (b*b==a*a+c*c) kt=1;
        if (c*c==a*a+b*b) kt=1;
        if ((a==b) and ((a<c) or (a>c)) and ((b<c) or (b>c))) kt=2;
        if ((b==c) and ((b<a) or (b>a)) and ((c<a) or (c>a))) kt=2;
        if ((c==a) and ((c<b) or (c>b)) and ((a<b) or (a>b))) kt=2;
        if ((a==c) and (b==c)) kt=3;
        if (kt==2) cout<<"Day la tam giac can";

else cout<<"Day khong la tam giac can";
    }
    else cout<<"Day khong la ba canh trong mot tam giac";
    return 0;
}

Program Bai1;

Uses crt;

Var a,b,c:integer;

Begin

CLRSCR;

Write('a='); Readln(a);

Write('b='); Readln(b);

Write('c='); Readln(c);

If (a*a=b*b+c*c) then Write('a,b,c la cac canh cua 1 tam giac vuong')

else('a,b,c khong phai la cac canh cua 1 tam giac vuong');

Readln

END.

program kiem_tra;

uses crt;

var a,b,c:integer;

begin

write('nhập số a');readln(a);

write('nhập số b');readln(b);

write('nhập số c');readln(c);

if(a*a=b*b+c*c)or(b*b=c*c+a*a)or(c*c=b*b+a*a)then writeln('đây là tam giác vuông') else writeln('đây là tam giác thường');

readln;

end.