Kayla’s work to find the surface area of a composite solid formed when a rectangular prism and rectangular pyramid are joined at their bases is shown below. SA = 2 ((5) (7)) + 2 ((6) (7)) + 2 (one-half (5) (9.3)) + 2 (one-half (6) (9.2)) = 255.7 square units What statement best describes Kayla’s error? She used the wrong expression for the lateral faces of the solid. She should have simplified 2 (one-half (5) (9.3)) + 2 (one-half (6) (9.2)). She left out one of faces of the solid. She should have simplified 2 ((5) (7)) + 2 ((6) (7)) + 2 (one-half (5) (9.3)) + 2 (one-half (6) (9.2)) + (5) (6). She used the wrong expression for the lateral faces of the solid and left out the base of the figure. She should have simplified 2 (one-half (5) (9.3)) + 2 (one-half (6) (9.2)) + (5) (6). She included the face where the pyramid and prism are joined together. She should have simplified 2 ((5) (7)) + 2 ((6) (7)) + 2 (one-half (5) (9.3)) + 2 (one-half (6) (9.2)) minus 2((5) (6)). SA = 2 ((5) (7)) + 2 ((6) (7)) + 2 (one-half (5) (9.3)) + 2 (one-half (6) (9.2)) = 255.7 square units

What statement best describes Kayla’s error?
She used the wrong expression for the lateral faces of the solid. She should have simplified 2 (one-half (5) (9.3)) + 2 (one-half (6) (9.2)).
She left out one of faces of the solid. She should have simplified 2 ((5) (7)) + 2 ((6) (7)) + 2 (one-half (5) (9.3)) + 2 (one-half (6) (9.2)) + (5) (6).
She used the wrong expression for the lateral faces of the solid and left out the base of the figure. She should have simplified 2 (one-half (5) (9.3)) + 2 (one-half (6) (9.2)) + (5) (6).
She included the face where the pyramid and prism are joined together. She should have simplified 2 ((5) (7)) + 2 ((6) (7)) + 2 (one-half (5) (9.3)) + 2 (one-half (6) (9.2)) minus 2((5) (6))