Yes it is the same thing ! :)
Mr. Gardener's annual interest rate is 8%.
40,000/500,000 = 0.08
The line of reflection is b
You can see it much easier if take away all the clutter. Redraw the diagram and take way a d and especially c.
You should be left with only line b and the two triangles. You can see it much easier if you do that. Then just look at the parallel lines of the triangles. They are right across from each other.
The second and the fourth