Given:
The school garden is 8.4 meters long and 6.4 meters wide.
so, the area of the garden = 8.4 x 6.4 = 53.76 square meters
And The section used to grow lettuce is 2.2 meters long and 0.8 meter wide
so, the area of the garden is used to grow lettuce= 2.2 x 0.8 = 1.76 square meters