Answer:

Step-by-step explanation:
Given a circle centre J
Let the radius of the circle =r
LK is tangent to circle J at point K
From the diagram attached
Theorem: The angle between a tangent and a radius is 90 degrees.
By the theorem above, Triangle JLK forms a right triangle with LJ as the hypotenuse.
Using Pythagoras Theorem:

The length of the radius, 
He can run 5 miles per hour
Answer:
=-52
Step-by-step explanation:
Answer:
D im not sure just my opinion
Answer:
EC = 15
Step-by-step explanation:
It appears that D, E, and F are the midpoints of their respective line segments (chords of the circumcircle). Hence EB = EC = 15.