Ican’t find the radius. i have found the center but it’s impossible for me to find the radius.

radius = 2 sqrt(5)

Step-by-step explanation:

We can find the radius from the endpoints

The diameter is the distance between the endpoint

The distance between  a and b is

d = sqrt( (x2-x1)^2 + (y2-y1)^2)

  = sqrt((11-3)^2 +(-8--4)^2)

  = sqrt((8^2+ (-8+4)^2)

   = sqrt(64+-4^2)

   = sqrt(64+16)

   = sqrt(80)

We know that sqrt(a b) = sqrt(a) sqrt(b)

sqrt(80) = sqrt(16) sqrt(5)

                4sqrt(5)

This is the diameter

The radius is 1/2 the diameter

radius  =1/2 (4 sqrt(5))

              radius = 2 sqrt(5)

They did not list the radius.  There is an error with the problem

since the airplane is moving with constant speed then the distance travelled can be calculated by x=u*t

in km/h would be:

x=640*3.5=2.240 km

in m/s would be:

u=640 km/h= 640.000 m/h =640.000/ 3600 m/s =177.8 m/s

t= 3.5 h= 3.5 * 3600 s=12.600 s

then x=u*t= 177.8*12.600= 2.240.280 m

what are ur choices?