Using the formula (n -2) x 180* we find that there is 4 sides (n) and in put it and simplify to make (2)x180*. From there we calculate there is 360* in this polygon, and subtract the degrees already provided. 360-210=150
He coud walk 5 meters in one hour because i did 60-12-12-12-12 and then you have a extra 12 so he got 5 meters in one hour part b he can 1 more further because 1 meter because before it was 12 hope explained it right