math - Get New Points from Angle Android -

i trying make re-sizable touch view made successfully. can find code how make view resizable on touch event.

it has 4 corners. can re-size rectangle dragging 1 of corner. want enhance logic , want put rotation in code. find angle when user touch center of 1 of edge of rectangle. problem can't new position of corners can redraw rectangle , rotation possible.

question : how can calculate 4 corners new position based on angle?.

if know angle rotate don't need calculate rectangle's vertices. simple way below

@override         protected void ondraw(canvas canvas) {             super.ondraw(canvas);             canvas.save();             canvas.rotate(60.0f);              paint.setcolor(color.black);             paint.setstyle(paint.style.stroke);              canvas.drawrect(10, 10, 100, 100, paint);             canvas.restore();         }