uses crt;

var r,cd,cr,s,p: real;

begin

clrscr;

write('Nhap ban kinh: '); readln(r);

cd:=r*2*3.14;

cr:=1/3*cd;

s:=cd*cr;

p:=(cd+cr)*2;

writeln('Dien tich la: ',s);

writeln('Chu vi la: ',p);

readln;

end.

const pi = 3.14;

var s,r:real;

begin

write('Nhap vao ban kinh R = ');readln(r);

s:=pi*r*r;

write('Dien tich hinh tron la ',s:10:2);

readln;

end.

Program HOC24;

var r,s: real;

begin

write('Nhap ban kinh: '); readln(r);

writeln('Dien tich la: ',r*r*3.14:6:2);

write('Chu vi la: ',r*2*3.14:6:2);

readln

end.

Chương trình chuvihinhtron_dientichhinhtron;

Sử dụng crt;

Trong đó R: số nguyên;

        S, C: thực;

Chòm sao Pi = 3,14;

Bắt đầu

   nhân viên văn thư;

Writeln ('R ='); Readln (R);

C: = Pi * 2 * R;

S: = Pi * R * R;

Writeln(‘Chu vi la C= ‘,C);

Writeln(‘Dien tich la S= ‘,S);

Readln

Chấm dứt.

#include <bits/stdc++.h>

using namespace std;

double r,cv,dt;

int main()

{

cin>>r;

cv=r*2*pi;

dt=r*r*pi;

cout<<fixed<<setprecsion(2)<<cv<<endl;

cout<<fixed<<setprecsion(2)<<dt;

return 0;

}

Câu 2: 

#include <bits/stdc++.h>

using namespace std;

double a,b,cv,dt;

int main()

{

cin>>a>>b;

cv=(a+b)*2;

dt=a*b;

cout<<"Chu vi la:"<<fixed<<setprecision(2)<<cv<<endl;

cout<<"Dien tich la:"<<fixed<<setprecision(2)<<dt;

return 0;

}

Program hoc24;

Uses crt;

Var r,S,C:real;

Begin

Write ('Ban kinh la');

Readln (r);

S:=r*r*3.14;

C:=r*2*3.14;

Writeln ('Chu vi la',C);

Writeln ('Dien tich la',S);

Readln;

End.

sau var có cần có dòng này : Const pi=3.14; không ạ ?

program TinhChuViVaDienTichHinhTron;

const
  pi: real = 34.4;

var r, chuVi, dienTich: real;

begin
 write('Nhap ban kinh cua hinh tron: ');
  readln(r);
     chuvi := 2 * pi * r;
  dientich := pi * sqr(r);
  writeln('Chu vi cua hinh tron la: ', chuvi:0:1);
  writeln('Dien tich cua hinh tron la: ', dientich:0:1);
end.

Bài này sai POP ơi

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