楕円を描画するには(Canvas.rawOval)

package jp.mediawing.android.test;

import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.RectF;
import android.os.Bundle;
import android.view.View;

public class TestActivity extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new DrawTest(this));
    }

    // Viewをextendsしたクラスを作成し描画処理をする
    static public class DrawTest extends View {

		public DrawTest(Context context) {
			super(context);
		}

        // 描画処理を記述
    	@Override
    	protected void onDraw(Canvas canvas) {
		    Paint paint = new Paint();
		    paint.setColor(Color.argb(255, 255, 255, 255));
			
			// (40.5, 20.5) から (60.5, 50.5)の矩形の内接円を描画
		    paint.setAntiAlias(false);
		    RectF ovalF = new RectF(40.5f, 20.5f, 60.5f, 50.5f);
		    canvas.drawOval(ovalF, paint);
			
			// アンチエイリアスで楕円を描画
			paint.setAntiAlias(true);
		    RectF ovalF = new RectF(40.5f, 20.5f, 60.5f, 50.5f);
		    canvas.drawOval(ovalF, paint);

			// 塗りつぶし無しで楕円を描画
			paint.setAntiAlias(true);
			paint.setStyle(Paint.Style.STROKE);
		    paint.setStrokeWidth(5);
		    RectF ovalF = new RectF(40.5f, 20.5f, 60.5f, 50.5f);
		    canvas.drawOval(ovalF, paint);		    
    	}
    }
}

Android Developers - Canvas