It's a polynomial of degree 2. Every polynomial of degree 2 is a parabola
You are correct with 80 on that answer. because since it is a polygon all sides add up to 180. you take 180 and subtract the number u have which is 100. u can double check your answer by looking at the angle. by looking its definitely less than 90 and not more than 90. it looks 80 to me and you can prove it by doing this 180-100=80
ANSWER=80°
4/7 = 8/14 = 12/21 = 16/28, etc
