Question

Only the circled ones

Answer 1

2.

M must be (0,0) since it coincides with the origin
R must be (a+b, √(a²-b²)).
The x-coordinate is b from A translated to the right by a.
The y-coordinate is the same as A.

(I think the square root is there to confuse you).

3.

R(0,0)
C(a,b) (same x as T, same Y as E)

5.

Not sure how to prove that.