Hey i really need with this i just started this math lesson and i am really confused. so me with this or explain the math

Acircle has a diameter will endpoints of (-2,8) and (6, 4). what is the center of the circle

Acyclist bike x distance at 10 miles per hour .and returns over the same path at 8 miles per hour. what is the cyclist average rate for the round trip in miles per hour ?

Keith runs 5 miles in 38 minutes. at the same rate, how many miles would he run in 57 minutes