Find angle a,b, c,d and e

Let's find the angles step by step.

Step 1: Find angle $a$.
Angle $a$ is $\angle CBE$. In $\triangle BCE$, the sum of angles is $180^\circ$.
We are given $\angle BCE = 50^\circ$ and $\angle BEC = 30^\circ$.

$$a + \angle BCE + \angle BEC = 180^\circ$$ $$a + 50^\circ + 30^\circ = 180^\circ$$ $$a + 80^\circ = 180^\circ$$ $$a = 180^\circ - 80^\circ$$ $$$$