Drawing a shape with line and curve combination

Question

I want to draw following shape. I have used bezier path but could not make those two corner curved. I have used

- (void)addArcWithCenter:(CGPoint)center radius:(CGFloat)radius startAngle:(CGFloat)startAngle endAngle:(CGFloat)endAngle clockwise:(BOOL)clockwise

- (void)addCurveToPoint:(CGPoint)endPoint controlPoint1:(CGPoint)controlPoint1 controlPoint2:(CGPoint)controlPoint2

- (void)addQuadCurveToPoint:(CGPoint)endPoint controlPoint:(CGPoint)controlPoint

but instead of giving curved line it's giving straight line.

Any idea how to do this.

CGFloat deltaX=0;
    CGFloat deltaY=0;

    CGFloat deltaXX=0;
    CGFloat deltaYY=0;

    CGFloat deltaXXX=0;
    CGFloat deltaYYY=0;

    CGFloat deltaXXXX=0;
    CGFloat deltaYYYY=0;

    CGFloat controlPoint1X=0;
    CGFloat controlPoint1Y=0;

    CGFloat controlPoint2X=0;
    CGFloat controlPoint2Y=0;


    deltaX=self.centrePoint.x+(currentPoint.x-self.centrePoint.x)/4;
    deltaY=self.centrePoint.y;

    deltaXX=self.centrePoint.x+(currentPoint.x-self.centrePoint.x)*3/8;
    deltaYY=self.centrePoint.y + (currentPoint.y-self.centrePoint.y)/4;

    deltaXXX=self.centrePoint.x+(currentPoint.x-self.centrePoint.x)*5/8;
    deltaYYY=self.centrePoint.y+(currentPoint.y-self.centrePoint.y)*3/4;

    deltaXXXX=self.centrePoint.x+(currentPoint.x-self.centrePoint.x)*3/4;
    deltaYYYY=currentPoint.y;

    controlPoint1X=deltaXX+(deltaXXX-deltaXX)/2;
    controlPoint1Y=deltaYY+(deltaYYY-deltaYY)/2;

    controlPoint2X=deltaXXX+(deltaXXXX-deltaXXX)/2;
    controlPoint2Y=deltaYYY+(deltaYYYY-deltaYYY)/2;

    CGPoint pointOne=CGPointMake(deltaX, deltaY);
    CGPoint pointTwo=CGPointMake(deltaXX, deltaYY);
    CGPoint pointThree=CGPointMake(deltaXXX, deltaYYY);
    CGPoint pointFour=CGPointMake(deltaXXXX, deltaYYYY);

    CGPoint controlPointOne=CGPointMake(controlPoint1X, controlPoint1Y);
    CGPoint controlPointTwo=CGPointMake(controlPoint2X, controlPoint2Y);

    UIBezierPath* aPath = [[UIBezierPath alloc]init];
    [aPath moveToPoint:self.centrePoint];
    [aPath setLineWidth:2.0f];
    [[UIColor blueColor] setFill];

   [aPath addLineToPoint:pointOne];
    [aPath moveToPoint:pointOne];

   [aPath addQuadCurveToPoint:pointTwo controlPoint:controlPointOne];

    [aPath moveToPoint:pointTwo];
    [aPath addLineToPoint:pointThree];

    [aPath moveToPoint:pointThree];
    [aPath addQuadCurveToPoint:pointFour controlPoint:controlPointTwo];

    [aPath addLineToPoint:currentPoint];


    [aPath stroke];

    for(UIBezierPath *bPath in self.arrPaths){
        [bPath stroke];
    }
    [self.arrPaths addObject:aPath];