# Notation in Geometry

I have this problem to solve:

The translation is:

Been the next angles: $\angle ABC$, $\angle DEF$ and $\angle GHI$, if $\angle ABC$ is "Parallel?" to $\angle DEF$ and $\angle GHI$ is parallel (again?) to the other 2 angles, then compute the measure of $\angle DEF$ if m(GHI)=75 grades.

But, obviously there are errors in it. What do not make sense to me is section marked in blue. $\angle ABC$ "Parallel?" to $\angle DEF$ and almost immediately again something that makes me think in Parallel angles.

Do I miss something here? How can an angle be "parallel" to another? Are they flat angles? ($180^\circ$)

• Skallab , can you please write the question (translated form )yourself instead of pasting pictures. It's hard to read . Commented Aug 3, 2013 at 0:22
• Making a simplification of the question is suppose it can be reduced to this: what means two parallel angles? In other words ABC//DEG express something like parallel angles. Do this exist? or I misunderstood the two parallel lines in-between the 2 angles Commented Aug 3, 2013 at 0:32