$\"\"$

Consider that the half ellipse formed by the gallery is centered at $\"\"$ .

The hall length $\"\"$ .

$\"\"$ .

The distance from the center to the foci is $\"\"$ .

Find the height of the gallery $\"\"$ .

$\"\"$

$\"\"$ .

The height of the gallery is $\"\"$ .

$\"\"$

The height of the gallery is $\"\"$ .