c++ to find area n circumference with entering radius

-1

int rad;

int rad;
float PI = 3.14 ,area,ci;
printf("\n Enter radius of a circle:");
scanf("%d",&rad);
area = PI*rad*rad;
printf("\narea of a circle is %f",area);
ci = 2*PI*rad;
printf("\ncircomeference of a circle is %f",ci);

One way to do this that looks a lot more like C++ code ...

// circle_calc101.cpp
// ask for radius of a circle and show area and circumference
#include <iostream>
#include <string>
#include <sstream>
int main(void)
{
std::string response;
float radius;
float pi = 355.0/113; // good approximation of pi
// loop input until a number has been entered
while(1)
{
std::cout << "Enter the radius: ";
std::cin >> response;
std::cin.ignore(1024, '\n'); // remove extra '\n'
// convert to number using a stringstream
std::istringstream convert(response);
if ( convert >> radius )
{
break;
}
}
std::cout << "radius of circle = " << radius << std::endl;
std::cout << "area of circle = " << pi*radius*radius << std::endl;
std::cout << "circumference of circle = " << 2*pi*radius << std::endl;
std::cin.sync(); // purge any \n
std::cin.get(); // console wait
return 0;
}

Write a C program that should create a 10 element array of random integers (0 to 9). The program should total all of the numbers in the odd positions of the array and compare them with the total of the numbers in the even positions of the array and indicate ...

Hi. so this is actually a continuation from another question of mineHere but i was advised to start a new thread as the original question was already answered.

This is the result of previous question answered :

I have a 2d matrix with dimension (3, n) called A, I want to calculate the normalization and cross product of two arrays (b,z) (see the code please) for each column (for the first column, then the second one and so on).
the function that I created to find the ...