The distance d from the center to the chord is found using the Pythagorean theorem, where half the chord is 15 cm (\(\frac{30}{2}\)). So d \(\sqrt{(r^2 - (\frac{chord}{2})^2}\) = \(\sqrt{(17^2 - 15^2)}\) = \(\sqrt{(289 - 225)}\) = \(\sqrt{64}\) = 8 cm.