Higher June 2017 Unit 2 Q11
11. In this question, you will be assessed on the quality of your organisation, communication and accuracy in writing.
The area of triangle ABD, shown in the diagram below, is 35 cm2.
AD = 5 cm and BC = 32 cm.
D is on the line AC, and BD is perpendicular to AC.
Diagram not drawn to scale
Calculate the size of angle \(x\).
You must show all your working. [5 + 2 OCW]
| Scheme | Marks | Comments |
|---|---|---|
| \(\dfrac{\text{BD} \times 5}{2} = 35\) | M1 | |
| BD = 14(cm) | A1 | May be seen on the diagram. Note : If they state that AB = 14cm, or indicate on the diagram that AB = 14cm then it is M0A0 as an incorrect method used for area of a right-angled triangle (however an unattached 14cm has to be given the benefit of the doubt and be awarded M1A1). |
| Cos x = \(\dfrac{14}{32}\) | M1 | FT ‘their stated or shown length BD’. FT has to use ‘their BD’ (not CD). |
| x = cos−1 0·4375 | m1 | |
| x = 64(°) | A1 | Accept answer rounded or truncated. [e.g. if their BD = 7, then accept 77(·36…°)] |
| Organisation and Communication. | OC1 | For OC1, candidates will be expected to:
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| Accuracy of writing. | W1 | For W1, candidates will be expected to:
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