Please check if the code correct for area of rectangle. Private Sub btnCompute$\_$Click$(...)$ Handles btnCompute.Click

Dim shapeNum As Integer

Dim length, width As Double

$$Input choice of shape and its dimensions

Rectangle

shapeNum $=$ CInt$($mtbSelection$.$Text$)$ 'Mask is $0$

Select shapeNum

length $=$ CDbl$($InputBox$("$Input the length of the rectangle: $"))$

width $=$ CDbl$($InputBox$("$Input the width of the rectangle: $"))$

txtArea.Text $=$ CStr$($length $*$ width$)$