Find the missing side. Leave your answer in simplest radical form.

Answer:
[tex] \sqrt{19} \: units[/tex]
Step-by-step explanation:
Given is a right angled triangle in which x represents the hypotenuse.
Therefore, by Pythagoras theorem:
[tex]x = \sqrt{( { \sqrt{10} })^{2} + {3}^{2} } \\ \\ = \sqrt{10 + 9} \\ \\ = \sqrt{19} \: units \\ [/tex]