Answer:
Disclaimer: I'm not sure because the numbers are too blurry. If my numbers don't match yours, just replace them in my work and recalculate them.
1) not tangent
2) tangent
3) not tangent
Explanation:
If they are tangent, the triangles formed will be right triangles.
Check using the Pythagorean theorem:
1) 18² = 14.4² + 11.7²
324 = 207.36 + 136.89
324 ≠344.25 not tangent
2) 7.5² = 4.5² + 6²
56.25 = 20.25 + 36
56.25 = 56.25 tangent
3) 20² = 12² + 12²
400 = 144 + 144
400 ≠ 288 not tangent