c# - Move a rectangle using angles -

i need move rectangle using angles. want change direction of moving rectangle when reaches location have given in code in if statement!

i need way can find out how move rectangle @ 60, 30, 60, 120, 150, 270 degrees!

suppose if

          circle.y>=this.height-80 

see this:

i need change direction of rectangle movement using angles! @ location reaches can change rectangle direction according angle of own choice! such that:

if(circle.y>=this.height-80)     move in direction of 90 degrees  if(circle.x>=this.width-80)     move in direction of 60 degree 

as can see in screen shot!

what have been trying is:

public partial class form1 : form {     rectangle circle;     double dx = 2;     double dy = 2;      public form1()     {         initializecomponent();         circle = new rectangle(10, 10, 40, 40);     }      private void form1_load(object sender, eventargs e)     {         this.refresh();     }      private void form1_paint(object sender, painteventargs e)     {         graphics g = e.graphics;         g.smoothingmode = smoothingmode.antialias;         g.fillellipse(new solidbrush(color.red), circle);     }      private void timer_tick(object sender, eventargs e)     {         circle.x += (int)dx;         circle.y += (int)dy;         if (circle.y>=this.height-80)         {             dy = -math.acos(0) * dy/dy; //here want change direction of circle @ 90 degrees should go vertically straight same speed         }         this.refresh();     } } 

the problem have been trying changing conditions to:

dy = -math.asin(1) * dy; dx = math.acos(0) * dx ; 

but in both cases nothing happening , direction remains same! want move circle in inverted upward direction @ 90 degrees when reach @

circle.y>=this.height-80 

you need draw rectangle again image display. created code moving , drawing rectangle on picturebox1, using defined circle-rectangle:

moving rectangle:

public void moverectangle(ref rectangle rectangle, double angle, double distance) {    double angleradians = (math.pi * (angle) / 180.0);    rectangle.x = (int)((double)rectangle.x - (math.cos(angleradians) * distance));    rectangle.y = (int)((double)rectangle.y - (math.sin(angleradians) * distance)); } 

drawing rectangle , displaying in picturebox:

public void drawrectangle(rectangle rectangle) {    bitmap bmp = new bitmap(picturebox1.width, picturebox1.height);    using (graphics g = graphics.fromimage(bmp))    {       g.smoothingmode = system.drawing.drawing2d.smoothingmode.antialias;       g.fillellipse(new solidbrush(color.red), rectangle);    }    picturebox1.image = bmp; } 

demo button click:

private void button1_click(object sender, eventargs e) {    moverectangle(ref circle, 90, 5);    drawrectangle(circle); }