We can obtain the correct answer using the Pythagorean theorem, but the book wants us to use a ruler to find the answer. Doing this, we find that the plane is going about 255 miles per hour.
You can help us out by revising, improving and updating this answer.Update this answer
After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.