How do I show the relationship between $I_n:=\int_{0}^{\pi}sin(x)^ndx$ and $I_n:=\frac{n-1}{n}I_{n-2}$

Question

How do I show the relationship between $$I_n:=\int_{0}^{\pi}sin(x)^ndx$$ and $$I_n:=\frac{n-1}{n}I_{n-2}$$ for when $n \in \mathbb{N}$ and $n≥2$