Higher November 2021 Paper 6 Q17
17 The diagram shows a pyramid ABCDE.
Not to scale
The pyramid has a square horizontal base ABCD with side 5.6 cm.
The vertex E is vertically above the centre O of the base.
The height OE of the pyramid is 6.8 cm.
Calculate the surface area of the pyramid.
You must show your working. [5]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| 113 to 114 with correct working | 5 | Check diagram for incorrect triangle. | “Correct working” requires evidence of at least M2 AND M1 ie correct triangle with Pythagoras and area of a triangle |
| Correct triangle or no triangle indicated: M2 for \(\sqrt{6.8^2 + 2.8^2}\) [= 7.35…] or for full alternative method or M1 for \(6.8^2 + 2.8^2\) [= 54.08 or 54.1] AND M2 for \(5.6 \times 5.6 + 4 \times \dfrac{1}{2} \times 5.6 \times \textit{their } 7.35\ldots\) or M1 for \(\dfrac{1}{2} \times 5.6 \times \textit{their } 7.35\ldots\) | eg Finding AC, AO, AE then the height (AC = 7.919…, AE = 7.868…) | ||
| Incorrect triangle indicated: M1 for complete Pythagoras to find hypotenuse with a maximum of one incorrect dimension | eg EB found as \(\sqrt{6.8^2 + 2.8^2}\) is using an incorrect dimension for OB | ||
| If 0 or M1 scored, instead award SC2 for answer 113 to 114 with no or insufficient working If 0 scored SC1 for 7.35 either correctly placed on diagram or with no working | |||