Hello what is the equation I got the height but what’s the equation I’m stuck plz help

Answer:
h = 20 cm
Step-by-step explanation:
The volume (V) of a square based prism is
V = area of base × h ( h is the height )
area of square base = 9 × 9 = 81 cm²
Hence
81h = 1620 ← equation to be solved
Divide both sides by 81
h = 20 cm