What is the lenght of X?

Answer:
[tex]x\approx 98.5[/tex]
Step-by-step explanation:
We can solve for x, which is the hypotenuse of a right triangle, using the Pythagorean Theorem:
[tex]a^2+b^2=c^2[/tex]
↓ plugging in the given side lengths
[tex]40^2 + 90^2 = x^2[/tex]
↓ taking the square root of both sides
[tex]x = \sqrt{40^2+90^2}[/tex]
↓ evaluating using a calculator
[tex]\boxed{x\approx 98.5}[/tex]