These aren't that hard--especially once you've done the first 13 questions. There are many 45-45-90 triangles in there.
14. ∠BCO = 45°
15. ∠GOF = 45°
16. ∠OFG = 45°
17. ∠GFH = 180° - ∠JFH = 58°
18. ∠FGH = 90°
19. ∠EFJ = 45°
20. ∠GOC = 180° (the points are collinear)
180=132+21+x
180=153+x
-153 -153
x=27
7/k - 2 = 5/8
7/k = 5/8 + 2
7/k = 2.625
7 = 2.625k
7/2.625 = 2.625k/2.625
2(2/3) = k
k = 2(2/3)
