The perimeter and area of the top of the child's desk are 120 inch and 864 inch² respectively.
Step-by-step explanation
Dimensions of the top of the adult's desk : Length = 54 inches and Width = 36 inches.
As the dimensions of the child's desk are
of the dimensions of the adult desk, so....
Length of child's desk
inches and
Width of child's desk
inches.
So, the perimeter of the top of the child's desk
inches.
and the area of the top of the child's desk
inch²