I need help with a few questions, if you answer one that is Great too!

Answer:
E is (5, 1)
Step-by-step explanation:
Let E be the point (x, y).
(-3 - x)^2 + ( 7 - y)^2 = 10^2 ( Pythagoras theorem)
Now 64^2 + 36^2 = 10^2 so we try:
(-3 - 5)^2 + ( 7- 1)^2 = 100
Giving x = 5 and y = 1 which looks right from the diagram.