Answer:
254 yds²
Explanation:
There are 6 faces of the prism we need to calculate the area of for a rectangular prism.
The base and top of the prism measure 9x7 yards each, so there are two faces with an area of 63 yds² (9 x 7 = 63)
The sides of the prism measure 4x7 yards each, so there are two faces with an area of 28 yds² (4 x 7 = 28)
The front and back face of the prism measure 9x4 yards each, so there are two faces with an area of 36 yds² (9 x 4 = 36)
The total surface area is
2(63) + 2(28) + 2(36) = 254 yds²