C = 2pi*r
Plug in the circumference
6.28 = 2*pi*r
3.14 = pi *r
plug in pi
3.14 = 3.14 * r
r = 1
Distance formula:

5 units-4.5 units=0.5 units
LM is 0.5 units longer than LM.
I think the answer is 0.25 seconds later
Hope this helped
The coordinate of the circumecenter of a triangle is A