Verified Answer :

a^2 + b^2 = c^2
3^2 + 10^2 = c^2
9 + 100 = c^2
109 = c^2
sq rt 109 = c
10.44 = c.....so the hypotenuse is 10.44 units

Hi there! :) 

Since we are looking for the hypotenuse, we will use the Pythagorean theorem.  
Which is:
\(a^2+b^2=c^2\)

We know the values of a and b  so let's plug them in
\(3^2+10^2=c^2\)
\(9+100=c^2\)
\(109=c^2\)
Square root both sides to cancel out the root
\(\sqrt{109} = \sqrt{c^2}\)

Final answer:

C=10.44