android - How can i draw a circle with a circle

Question

How can i do that? Is there an example for that? Can you show me ?

For ex. I have an circle like that

RadialGradient gradient = new RadialGradient(0, 0, 40, new int[]{Color.RED, Color.YELLOW}, new float[] {1,0}, android.graphics.Shader.TileMode.CLAMP);
paint2.setShader(gradient);
canvas.drawCircle(this.getWidth()/2, this.getHeight()/2, 40, paint2);

How this circle can draw a circle?