Degree of ploynominal is the largest exponent you find, which is here the 4x to the 6th. there are only two terms here.
The variable can be g for games being bowled and the expression is 25g
We can get the angle with
tan a= opposite side / adjacent side = 35ft/ 50ft=0.7, so a = arctan(0.7)=35°
look at the image