Approach to or just approach?

Dear vocabulary learners! There are some nouns and verbs which can be confusing because of prepositions. I would like to focus on one example today:

1.     An approach to - http://www.macmillandictionary.com/dictionary/british/approach_1#approach_1__3

2.     To approach –

http://www.macmillandictionary.com/dictionary/british/approach_2