Answer:
a^2 + b^2 = c^2 : a and b represent the short sides of the triangle (i.e., the ones that touch the right angle), while c represents the hypotenuse or the long side (does not touch the right angle)
Explanation:
so...
1. 9^2 + b^2 = 10^2
81 + b^2 = 100
b^2 = 100 - 81 or 19
b = square root of 19 or about 4.35
3. 16^2 + b^2 = 19^2
256 + b^2 = 361
b^2 = 105
b = square root of 105 or about 10.24
5. 2^2 + b^2 = 8^2
4 + b^2 = 64
b^2 = 60
b = square root of 60 or about 7.745
7. 2^2 + b^2 = 5^2
4 + b^2 = 25
b^2 = 21
b = square root of 21 or about 4.58