To derive the formula for the surface area (SA) of the rectangular pyramid, we need to consider both the area of the base and the areas of the triangular faces.
- The area of the base (rectangle) is represented as \( A_{\text{base}} \).
- Each triangular face facing up and down is labeled \( A_{\text{face 1}} \).
- Each triangular face on the sides is labeled \( A_{\text{face 2}} \).
The base contributes \( A_{\text{base}} \) to the surface area, while each triangular face on the base contributes as follows:
- There are 2 triangular faces labeled \( A_{\text{face 1}} \) (one on the top and one on the bottom).
- There are also 2 triangular faces labeled \( A_{\text{face 2}} \) (one on the right and one on the left).
Therefore, the total surface area (SA) can be expressed as:
\[ SA = A_{\text{base}} + 2 \times A_{\text{face 1}} + 2 \times A_{\text{face 2}} \]
Thus, the correct option for the formula for the surface area of the rectangular pyramid is:
SA = Abase + 2 × Aface 1 + 2 × Aface 2