Question

If true then enter $1$ and if false then enter $0$

Can two adjacent angles be supplementary?

Answer 1

Yes.

Two adjacent angles can be supplementary if their sum is 180 degrees. This is only possible if both angles are right angles or if one is acute and the other is an obtuse angle and their sum is 180 degrees.
E.g.
${110}^o+{70}^o={180}^o{90}^o+{90}^o={180}^o$