An angle is made up of two rays starting from a common initial point called vertex.
In the figure above, O is the vertex.
Angles shown in the figure are
1. ∠AOB = 40∘
2. ∠BOC = 20∘
3. ∠COD = 30∘
4. ∠AOB + ∠BOC = 40∘+ 20∘ = 60∘
5. ∠AOB + ∠BOC + ∠COD = 40∘ + 20∘ + 30∘ = 90∘
6. ∠BOC + ∠COD = 20∘ + 30∘ = 50∘
Therefore, there are 6 angles.