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

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.