Answer:
1. x = 15
2. x = 26
3. x = 7.6157731059 (you can round this answer to 8 or 7.6)
4. x = 11.7
5. x = 25
6. x = 1.4
7. x = 22.5
8. x = 38.4
9. x = 10.3 v = 5.8
For some of them, I had to use estimation.
I used this formula : a^2 + b^2 = c^2