Answer:
Corn was planted in 24 sq.ft. of the vegetable garden.
Step-by-step explanation:
Length of garden = 9 ft
width of garden = 8 ft
Hence we will first find the total area of garden.
Total area of garden = length × width = 
He planted 1/2 of the garden with vegetables.
Hence.
Area of Vegetables garden = 
He planted tomatoes in 1/3 of the vegetable garden and corn in the rest
Area in which tomatoes was planted = 
Hence Area in which corn were planted = Area of Vegetables garden - Area in which tomatoes was planted = 
Hence Area of vegetable garden in which corn was planted is 24 sq.ft.