Does this chart show a heliport in class D airspace without a control tower?
The triangular area you’re referring to is actually the LAX class D airspace.
The heliport itself is uncontrolled. It is not that uncommon for an uncontrolled heliport or airport to be within the surface area of a controlled airport. Departing aircraft are required to contact tower as soon as practical after takeoff, and arriving aircraft are told that landing is at their own risk.