void CGPathAddPath (
  CGMutablePathRef path1,     // The mutable path to change.
  const CGAffineTransform *m, // A pointer to an affine transformation matrix, or NULL if no transformation is needed. If > specified, Quartz applies the transformation to path2 before it is added to path1.
  CGPathRef path2             // The path to add.
);

UIBezierPath *endPath =  [UIBezierPath bezierPath];
[endPath appendPath:leftLine];
[endPath appendPath:rightLine];
[endPath appendPath:midLine];