Tangent metric spaces to starlike sets on the plane

Oleksiy Dovgoshey, Fahreddin Abdullayev, Mehmet Kucukaslan

Let $A\subseteq \mathbb{C}$ be a starlike set with a center $a$. We prove that every tangent space to $A$ at the point $a$ is isometric to the smallest closed cone, with the vertex $…