Elevation Decline icon

<svg width="24" height="24" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="currentColor"><path d="M21,21H3V11.25L9.45,15L13.22,12.8L21,17.29V21M3,8.94V6.75L9.45,10.5L13.22,8.3L21,12.79V15L13.22,10.5L9.45,12.67L3,8.94Z"/></svg>