Answer:
16 degrees
Step-by-step explanation:
x+56=72
x=16 degrees
[tex] {x}^{o} + {56}^{o} = {72}^{o} \\ {x}^{o} = {72}^{o} - {56}^{o} \\ {x}^{o} = {16}^{o} \\ [/tex]