Answer:
3[tex]\sqrt{10}[/tex] = x
Step-by-step explanation:
This is a right triangle and in right triangles the sum of square length of two legs is equal to square length of hypotenuse.
Now let x represent the third side:
9^2 + 10^2 = x^2
81 + 100 = x^2
181 = x^2 find the root for both sides
3[tex]\sqrt{10}[/tex] = x