Решить в Visual Basic

Private Sub Command1_Click()
Dim a As Single, b As Single, c As Single, D As Single
Dim x1, x2, answer
a = InputBox("a")
b = InputBox("b")
c = InputBox("c")
D = b ^ 2 - 4 * a * c
If D < 0 Then
answer = "D<0 . Вещественных корней не существует"
ElseIf D = 0 Then
answer = (-b) / (2 * a)
Else
x1 = (-b - Sqr(D)) / (2 * a)
x2 = (-b + Sqr(D)) / (2 * a)
answer = "D=" & D & Chr(13) & "x1= " & x1 & Chr(13) & "x2= " & x2
End If
MsgBox answer
End Sub

Private Sub Command1_Click()
Dim a As Single, R As Single
Dim answer as long
a = InputBox("a")
R = InputBox("R")
answer = (2 * 3.14 * R * 360) / a  'это если угол в градусах, если в радианах, то 360 заменить на 6.28
MsgBox answer
End Sub

Private Sub Command1_Click()
Dim a As Single, R As Single
Dim answer as long
a = InputBox("a")
R = InputBox("R")
answer = (3.14 * R^2) * (360 / a)  'это если угол в градусах, если в радианах, то 360 заменить на 6.28
MsgBox answer
End Sub

Private Sub Command1_Click()
Dim R As Single
Dim answer as long
R = InputBox("R")
answer = (3.14 * R ^ 2) ^ (1 / 2)
MsgBox answer
End Sub

(2 * 3.14 * R * a) / 360

(3.14 * R^2) * (a / 360)