Let the number of sides of the polygon be n.
Length of each side of the polygon = 3.8 cm
∴ Perimeter of the polygon = (3.8 n) cm
But it is given that its perimeter is 22.8 cm.
∴ (3.8 n) cm = 22.8 cm
⇒ n = = = 6
Hence, the given polygon has six sides.