Answer:
21.5
Explanation:
x is the radius of the circle.
If we draw a line from the circle's center to either end of the horizontal line, that line will also be a radius, so it will have length x. This forms a right triangle with side lengths 10 and 19 and hypotenuse x.
Using Pythagorean Theorem:
c² = a² + b²
x² = 10² + 19²
x² = 461
x ≈ 21.5