They are not the same shape or size. hope this helps!
6.40x+9.90(154-x)=1230.90
Solve for x
X=84 for child
154-84=70 for adults
idk i am in 6th grade idk
The radius is 2 yards...
Formula for circumference is

so divide your circumference by 3.14 or pi and you get 4 the square root of 4 is 2.
Hope this helps!
Let me know if you can see this photo