The shadow of a 3-foot-tall child who stands next to the statue would be 4.5 feet long.
To find the length of the shadow cast by the child, we can use the formula:
Shadow length = (Height of object / Height of object casting shadow) * Shadow length of object casting shadow
Plugging in the given values, we get:
Shadow length = (3 ft / 12 ft) * 18 ft
= (1/4) * 18 ft
= 4.5 ft
Therefore, the shadow of the 3-foot-tall child would be 4.5 feet long.