**Definition 5.1**:

Let $z_{1},z_{2},z_{3}\in \mathbb {C}$ . Then the **triangle defined by $z_{1},z_{2},z_{3}$ ** is defined to be the set

- .

**Lemma 5.2**:

Let $S\subseteq \mathbb {C}$ and $f\in H(S)$ .

**Definition 5.3**:

Let $S\subseteq \mathbb {C}$ . We call $S$ **starshaped** if and only if there exists a $z^{*}\in S$ such that

- $\forall z\in S:[z*,z]\subseteq \mathbb {C}$ .

**Theorem 5.4**: