かどうか is an expression in Japanese which combines the ‘or’ meaning of か, with the ‘how’ meaning of どう. (A) かどうか (B) is regularly translated as ‘whether or not (A), (B)’.
To use かどうか, simply attach it to the end of any phrase that you want to express the ‘or’ use of か about, then add the (B) phrase.

• サチコと付（つ）き合（あ）うかどうか分（わ）からない。
  I don't know whether or not I will go out with Sachiko.
• 水（みず）が汚（きたな）いからこの川（かわ）が深（ふか）いかどうか分（わ）からない。
  Since the water is dirty, I don't know whether or not this river is deep.
• この携帯（けいたい）が便利（べんり）かどうか分（わ）からない。
  I don't know whether or not this cell phone is useful.
• 目（め）が悪（わる）いからあそこにいるのが父親（ちちおや）かどうかわからない。
  Because I have bad eyes, I don't know whether or not the person over there is my father.

Although ‘whether or not’ is the standard translation, the more literal translation of かどうか is ‘if it’s (A), or however it is, (B)’.