Microsoft Small Basic Triangle issue

So basically, I'm a beginner trying to make a game on Small Basic. It's a space themed game, and there are going to be 2 spaceships, one red and one blue. So far, I'm coding the blue one and I want the controls to be like up arrow for blue to go forwards, down arrow to go back, left arrow to rotate left, and right arrow to rotate right. For this, I used the BluePlayer = Shapes.AddTriangle command, however, when I try to rotate or move the triangle, it disappears off screen. Please help. I will leave my code below for you to try to tinker around with it. Please comment if you come to any conclusion.

Code:

' Space Fighting Game"

' Setup

GraphicsWindow.BackgroundColor = "black"

GWW = 1025

GWH = 500

GraphicsWindow.Width = GWW

GraphicsWindow.Height = GWH

' Blue Player Setup

GraphicsWindow.BrushColor = "Aqua"

BlueX1 = GWW - 25

BlueY1 = GWH / 2 - 10

BlueX2 = BlueX1

BlueY2 = GWH / 2 + 10

BlueX3 = GWW - 50

BlueY3 = GWH / 2

PlayerBlue = Shapes.AddTriangle(BlueX1, BlueY1, BlueX2, BlueY2, BlueX3, BlueY3)

GraphicsWindow.KeyDown = WhenKeyPressed

Sub WhenKeyPressed

If GraphicsWindow.LastKey = "Up" Then

GraphicsWindow.Clear()

BlueX1 = BlueX1 - 10

BlueX2 = BlueX2 - 10

BlueX3 = BlueX3 - 10

PlayerBlue = Shapes.AddTriangle(BlueX1, BlueY1, BlueX2, BlueY2, BlueX3, BlueY3)

ElseIf GraphicsWindow.LastKey = "Down" Then

GraphicsWindow.Clear()

BlueX1 = BlueX1 + 10

BlueX2 = BlueX2 + 10

BlueX3 = BlueX3 + 10

PlayerBlue = Shapes.AddTriangle(BlueX1, BlueY1, BlueX2, BlueY2, BlueX3, BlueY3)

ElseIf GraphicsWindow.LastKey = "Left" Then

Shapes.Rotate(PlayerBlue, 100) 

Shapes.Move

EndIf

EndSub