Animating Slice of Donut

DonutSlice.m

        float radius = 300;

        CAShapeLayer *donut = [CAShapeLayer layer];
        donut.bounds = CGRectMake(0,0,radius, radius);
        donut.cornerRadius = radius/2;
        donut.borderWidth = 2;
        donut.borderColor = [UIColor redColor].CGColor;
        [self.layer addSublayer:donut];
        
        
        CAShapeLayer *progressiveDonut = [CAShapeLayer layer];
        progressiveDonut.bounds = donut.bounds;
        progressiveDonut.path = donut.path;
        progressiveDonut.cornerRadius = donut.cornerRadius;
        progressiveDonut.backgroundColor = nil;


        progressiveDonut.strokeColor = [UIColor orangeColor].CGColor;
        progressiveDonut.lineWidth = 4;
        progressiveDonut.strokeStart = 0.0;
        progressiveDonut.strokeEnd = 0.3;
        progressiveDonut.lineJoin = kCALineJoinBevel;
        
        progressiveDonut.borderWidth = 3;
        progressiveDonut.borderColor = [UIColor blueColor].CGColor;
        
        
        [self.layer addSublayer:progressiveDonut];