Question

http://gyazo.com/ec2fc72812f20e9a87c84f71b35bb826 this one is confusing to me. :/

Answer 1

This is just using the property of vertical angles when two lines intersect, which is as follows. If we have two lines crossing like so:

Then the following angles will be equal:
a=c
b=d
Does this help you with finding your answer?

Answer 2

no i still do not understand/

Answer 3

Well let me draw your question out:

Remember the last diagram I showed? Basically it says that if two straight lines intersect, then the angles opposite each other will be equal.
Does this make sense now? If not then I will be glad to give another example to help explain it.