How many cubic yards are in 12x12x4?
18 feet = 9 yards
12 feet = 4 yards
9 yards X 4 yards = 36 square yards
A cubic yard is 36" x 36 " x 36 "
36 " / 4" = 9 (4" sections)
Thus, 1 cubic yard has 9 square yard layers which are 4"
thick
So, 1 cubic yard will cover 9 square yards 4" thick
So, 4 cubic yards will cover 36 square yards which are each 4"
thick