Given a radius of circle , we have to find the area of circle and print the area of circle.

So what is **area of circle** ?

area of circle is 3.14 * radius * radius;

**Example:**

**Input:**5
**Output:**78.5

**Logic:**

**STEP 1**: radius r of circle. is given already. we have to find the area
**STEP 2**:area=3.14*r*r;
**STEP 3**:print the area

**Code**

#include<bits/stdc++.h> using namespace std; int main() { cout<<"enter radius "<<endl; double r; cin>>r; double area=3.14*r*r; cout<<"area" << " "<<area<<endl; }

**Ouput:**

5 78.5

**Time Complexity**:O(N)

**Space Complexity**:O(1)