D + q = 32....d = 32 - q
0.10d + 0.25q = 6.50
0.10(32 - q) + 0.25q = 6.50
3.20 - 0.10q + 0.25q = 6.50
-0.10q + 0.25q = 6.50 - 3.20
0.15q = 3.30
q = 3.30 / 0.15
q = 22 <=== 22 quarters
d + q = 32
d + 22= 32
d = 32 - 22
d = 10 <=== 10 dimes
The x coordinate of S will be 1/2 * 2a = a.
and since the half triangle is 30-60-90 the y coordinate will be sqrt3 a
so S is (a , sqrt3a)