Question

kaylas work
sa = 2((5)(7)) + 2((6)(7)) + 2(\frac{1}{2}(5)(9.3)) + 2(\frac{1}{2}(6)(9.2)) = 255.7 square units
what statement best describes kaylas error?
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(\frac{1}{2}(5)(7 + 9.3)) + 2(\frac{1}{2}(6)(7 + 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(\frac{1}{2}(5)(9.3)) + 2(\frac{1}{2}(6)(9.2)) - 2
she left out one of faces of the solid. she should have simplified 2((5)(7)) + 2((6)(7)) + 2(\frac{1}{2}(5)(9.3)) + 2(\frac{1}{2}(6)(9.2)) + (
she used the wrong expression for the lateral faces of the solid. she should have simplified 2(\frac{1}{2}(5)(7 + 9.3)) + 2(\frac{1}{2}(6)(7 + 9.2)).

Explanation:

When calculating the surface area of a combined solid (a prism - pyramid combination), the face where they are joined is not part of the outer - surface area. Kayla included this internal face in her calculation.

Answer:

She included the face where the pyramid and prism are joined together. She should have simplified \(2((5)(7)) + 2((6)(7))+2(\frac{1}{2}(5)(9.3)) + 2(\frac{1}{2}(6)(9.2))-2\).