Answer
See the answer below.
Work Step by Step
a) The OCN angles are 120° because the central carbon is in trigonal planar geometry.
The CNH angles are 109° because the central nitrogen is in pyramidal geometry from the tetrahedral archetype.
b) The double bond, because bond length decreases with bond order.
c) Most likely to the oxygens, but the nitrogens are a viable alternative.
