Решение:

1. $$ \sqrt{34^2 - 16^2} = \sqrt{1156 - 256} = \sqrt{900} = 30 $$
2. $$ \sqrt{35^2 + 12^2} = \sqrt{1225 + 144} = \sqrt{1369} = 37 $$
3. $$ \sqrt{39^2 - 36^2} = \sqrt{1521 - 1296} = \sqrt{225} = 15 $$
4. $$ \sqrt{40^2 + 9^2} = \sqrt{1600 + 81} = \sqrt{1681} = 41 $$

Ответ:

1. 30
2. 37
3. 15
4. 41