Help please / need help

Question

This is another version in a series of assignment to implement a program to calculate the properties of various geometric shapes. In this assignment, you will enhance the functionality from the previous version with the ability to perform calculations for triangles (isosceles) and rectangles as well as circle shapes.

Your program must have a menu system with choices of 1-4. If the user enters 1, the program should ask for the radius of the circle and then display its area. Use the following formula: area = πr2. If the user enters 2, the program should ask for the length and width of the rectangle and then display the rectangle’s area. Use the following formula: area = length * width. If the user enters 3 the program should ask for the length of the triangle’s base and its height, and then display its area. Use the following formula: area = 0.5 * base * height. If the user enters 4, the program should print the message without quotations: "Thank you for using the program. Bye…", and the program ends.

Input Validation:

1. Display an error message if the user enters a number outside the range of 1 through 4 when selecting an item from the menu.
2. Do not accept negative values for the circle’s radius, the rectangle’s length or width, or the triangle’s base or height.

The output should look something like this:
Welcome to Geometry Calculator!
1. Calculate the Area of a Circle
2. Calculate the Area of a Rectangle
3. Calculate the Area of a Triangle
4. Quit Enter your choice (1-4): 1
Enter the circle radius: 2
The area of the circle is: 12.5664

1. Calculate the Area of a Circle
2. Calculate the Area of a Rectangle
3. Calculate the Area of a Triangle
4. Quit Enter your choice (1-4): 2
Enter the rectangle length: 2
Enter the rectangle width: 4.2
The area of the rectangle is: 6.4000

1. Calculate the Area of a Circle
2. Calculate the Area of a Rectangle
3. Calculate the Area of a Triangle
4. Quit Enter your choice (1-4): 3
Enter the triangle base: 3
Enter the triangle height: 3.2
The area of the triangle is: 4.8000

Answer 1

First of all, use if conditions to bind your values between the given conditions like

if (area>=0 && lenght>=0 && breadth>==0)

then your remaining programme

Now, you have to use switch case operators to switch (as to let the user choose what it wants to calculate ). It is optional though than you use switch operator.

Switch operators are used as follows:

like, first of all, let the user select what it wants

so,  printf("What do you want");

  scanf("\n1:Addition\n2:Substraction etc etc");

scanf("%d",&ch);

{switch(ch)

{case 1:

value=a+b;

break;

case 2:

value = a-b; break; ..........etc etc i hope this will help!