<span>It must be the same as it was when constructing the arc above P.</span>
36 should be added to both sides because 12/2= 6 then you square 6 to get 36 and that should be it.
The answer to your question is 11
The calculations for 2, 4, 8 year can be derived as follows,
For simple interest:
S.I = 
P= principle
T= Time
R= Rate
For 2 year;
S.I =
= $224
Amount = $2224
For 4 year;
S.I =
= $448
Amount = $2448
For 8 year;
S.I =
= $896
Amount = $2896
The answer would be Acute angles