Given a circle with radius, r:

• the formula for the area of the circle is: pi * r ^ 2 (Note: r ^ 2 means r squared)
• the formula for the circumference of the circle is: 2 * pi * r

Create a program that asks the user to enter the radius of a circle. The program should then display the area and circumference of the circle. You may use the value of 3.14 as an approximate value of pi.

Create a program that allows the user to enter numbers into 3 different text boxes. When the user presses a button, the values in the textboxes should change as follows:

• The value in the first textbox should be replaced with the value from the third textbox
• The value in the 2nd textbox should be replaced with one more than the value which was originally in the first textbox
• The value in the 3rd textbox should be replaced with one more than the value which was originally in the 2nd textbox

HINT: You will need to use at least one variable.

For example if the following were the original values

• First textbox: 10
• Second textbox: 20
• Third textbox: 30

After pressing the button once, the new values should be

• First textbox: 30
• Second textbox: 11
• Third textbox: 21

After pressing the button a 2nd time, the new values should be

• First textbox: 21
• Second textbox: 31
• Third textbox: 12

etc ...

Write a program with the following user interface:

When the user clicks on Button1 and Button2 NOTHING SHOULD BE DISPLAYED.

When the user clicks on the button, "Count # of Clicks", a message box should be displayed that shows the following information

• The number of times that the user clicked on Button1
• The number of times that the user clicked on Button2
• The total number of times that the user clicked on either Button1 or Button2

When the user clicks on the "Reset Count" button, nothing should be displayed, but the counts should go back to zero

EXAMPLE:

User clicks on Button1 twice, then on Button2 once, then on the button, "Count # of Clicks"

User then clicks Button2 three more times and then clicks on the button, "Count # of Clicks"

User then clicks the "Reset Counts" button and then clicks on the button, "Count # of Clicks"

User then clicks on Button1 once, then on Button2 once, then on the button, "Count # of Clicks"

The purpose of this assignment is for you to get used to entering code with nested if/elseif/else statements.

Create a new VB project with the following interface:

The user of the program enters a number and presses the button. A series of different MessageBoxes will then be displayed. The contents of the message boxes depend on what number the user entered.

The code for the button's click handler can be seen by cliking here. The name of the button in the project is btnDoit and the name of the textbox is tbNum. IMPORTANT: When you type in the code, make SURE that you press ENTER after each time that you type the words THEN and ELSE. If you don't then VB will format the code in a different way than we learned about.

What messages boxes will be displayed when the user enters the following numbers?

• 1
• 3
• 40
• 55
• 72
• 73
• 74
• 81
• 100
• 200

Make sure that you are able to figure out the answers by just looking at the code. To check your answers you may try running the program and see what you get.

Question: Given the following code, what will the program display when the user clicks "Button1" ?

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim s As String
        Dim i, j As Integer
        j = 3
        For i = 2 To 4
            j = j + i * 2
            s = j.ToString() & j.ToString() & s
            MessageBox.Show(s)
        Next i
    End Sub

Write a program that asks the user to enter a number. The program should then compute the sum of "N + N*(N+1)" where N loops from 1 through the number that the user entered. For example, if the user enters the number 4 then the program should compute the following value and display the result (i.e. 40):

(1*2) + (2*3) + (3*4) + (4*5)

=40