In a circle of diameter 30 cm, the length of a chord is 15 cm.

Diameter = 30 cm

Length of chord $=15 \mathrm{~cm}$

Radius $=15 \mathrm{~cm}[\mathrm{r}=0.5 \times$ diameter $]$

Since the radius is equal to the length of the chord

Hence the formed triangle in the circle is an equilateral triangle.

$\theta=60^{\circ}$

We know that $\mathrm{I}=\mathrm{r} \times \theta$

$I=15 \times 60 \times \frac{\pi}{180}=5 \times \pi=5 \times 3.14=15.7$

Therefore, the length of the minor arc is $15.7 \mathrm{~cm}$