ugh I hated learning these, they are so confusing
so we need to isolate the part that has h
so we would subtract 2r^2
T - 2r^2 = 2rh
the we would need to divide by 2r
(T - 2r^2)/2r = h
but we can simplify the left side
T/2r - 2r = h
I think that's right but not 100% sure