Given a scientific passage and an answer, generate a question for the given answer.
Q: Passage: As you can see in Figure above , the electric and magnetic fields that make up an electromagnetic wave occur are at right angles to each other. Both fields are also at right angles to the direction that the wave travels. Therefore, an electromagnetic wave is a transverse wave. Answer: transverse wave
A:
Because the fields that make up an electromagnetic wave are at right angles to each other and to the direction that the wave travels, an electromagnetic wave is considered what?