The answer is definitely not 7.777777
Answer:
Center: (4,8)
Radius: 2.5
Equation: 
Step-by-step explanation:
It was given that; the endpoints of the longest chord on a circle are (4, 5.5) and (4, 10.5).
Note that the longest chord is the diameter;
The midpoint of the ends of the diameter gives us the center;
Use the midpoint formula;

The center is at; 
To find the radius, use the distance formula to find the distance from the center to one of the endpoints.
The distance formula is;




The equation of the circle in standard form is given by;

We substitute the center and the radius into the formula to get;


Answer:
x = 8sqrt3
y=8
Step-by-step explanation:
cos60=y/16
y=16cos60
y=16x1/2
y=8
sin60=x/16
x=16sin60
x=(16sqrt3)/2
x=8sqrt3
Use the distance formula.
Points S and W.



~3.6
Points S and T




~3.6
Points T and U




~3.1
Points U and V



~4
Points V and W




~3.3
Add all these together.
3.3 + 3.1 + 4 + 3.1 + 3.6
≈17