You can put this solution on YOUR website! the center of the circle lies on the line connecting the midpoints of the chords, this line is also perpendicular to the chords
let x equal the distance from the center to the 30 cm chord, so 23-x equals the distance to the 16 cm chord
a right triangle is formed by x, half of the 30 cm chord and the radius
similarly, another right triangle is formed by 23-x, half of the 16 cm chord and the radius
using Pythagoras, and ... so ... 225=593-46x ... x=8