Supplementary angles are:
∠a and ∠b
∠b and ∠d
∠c and ∠d
∠a and ∠c
∠e and ∠f
∠f and ∠h
∠g and ∠h
∠e and ∠g
∠b and ∠h
∠d and ∠f
∠a and ∠e
∠c and ∠g
∠a and ∠f
∠b and ∠e
∠c and ∠h
∠d and ∠g