Solution Source Code

Code Overview

1. Header Files and Namespace:

• <iostream> is included for input and output operations.
• <string> is included for potential future use (not used in this program).
• <cmath> is included to use pow() for exponentiation (D²).
• using namespace std; allows the use of standard functions without prefixing them with std::.

2. User Input Function (ReadDiameter)

• Prompts the user to enter the diameter (D) of a circle.
• Reads and returns the diameter.

3. Area Calculation Function (CircleAreaByDiameter)

• Takes the diameter (D) as input.
• Uses the formula for the area of a circle in terms of diameter:

• This is implemented as:

float Area = (pow(D, 2) * PI) / 4;

• • pow(D, 2) calculates D².
  • PI is defined as 3.141592653589793238 for precise calculations.
  • The division by 4 ensures correct computation of the area using the given formula.
• Returns the computed area.

4. Output Function (PrintResult)

• Receives the computed area as a parameter.
• Prints "Circle Area = [Area]".

5. Program Execution (main())

• Calls ReadDiameter() to get user input.
• Calls CircleAreaByDiameter() to compute the area.
• Calls PrintResult() to display the result.
• Returns 0 to indicate successful execution.

This structured explanation ensures clarity and ease of understanding.