TheMathsTutor works out the answer to the question.

Check out KeysToMaths1 for more tutorials and worked solutions: https://www.youtube.com/channel/UCOYoe9L9R13HGUIhszjkeug

Useful tutorial to provide intuition in methods of showing that angles are the same in measure when doing proofs, also ties into theorem 12. More free lessons at: http://www.khanacademy.org/video?v=eF6zYNzlZKQ Note: All Khan Academy content is available for free at (www.khanacademy.org)

A good example of a question where you need to give a combination of mathematical and worded answers.