Essentially, the rule goes as so: odd + odd = even, even + even = even.
Although that may not be the answer you're looking for, it is a math rule that is never debunked and essentially the premises for why you get an even sum practically always depending on the numbers.
Hope this helps!
Step-by-step explanation:
the formula to calculate a circumference is

(consider x as the diameter)
so I'll be noting the circumference as C alongside the circle's ranking
a.

b.

c.

hope I helped
90 + 49 = 139
180 - 139 = 41
x = 41
Answer:
the one on the right looks best for the slope because the slope is a lot larger than the one on the right the one on the right is smaller but a few inches few times I don't know you might want to check it before I actually answer it for you so I hope you found this kind of helpful thank you bye