Answer:
x = sqrt(105)
Step-by-step explanation:
Since this is a right triangle, we can use the Pythagorean theorem
a^2 + b^2 = c^2 where a and b are the legs and c is the hypotenuse
16^2 + x^2 = 19^2
256 + x^2 = 361
x^2 = 361 -256
x^2 =105
Take the square root of each side
sqrt(x^2) = sqrt(105)
x = sqrt(105)
