O-LevelMathematicsTrigonometry4024/22 · May/June 2015 · Q511 Marks
In the diagram, AB = 8 cm, AC = 11 cm and DC = 6.5 cm. BÂD = 26° and DÂC = 30°. [Figure 5.1]
- (a)Calculate BC.[4]
- (b)Calculate the obtuse angle ADC.[3]
- (c)Find the percentage of triangle ABC that has been shaded.[4]
This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.
Mark scheme
Marking points from the official mark scheme (May/June 2015). The mark or mark type is shown in brackets.
- [4] M2 for BC2 = 82 + 112− 2 × 8 × 11 cos 56 Or M1 for 82 + 11²± (2) × 8 × 11 cos 56; B1 for 86.5 to 86.6; (±) 9.3(0) to 9.31
- [3] M2 for (sin ADC = 11 sin 30 / 6.5) , or 57.7 to 57.8, or 58 Or M1 for sin ADC / 11 = sin 30 / 6.5 oe; 122.2 to 122.3
- [4] B1 for 27.7 to 27.8 seen; M1 for 1/2 × 11 × 8 × sin 56 (= 36.478...) or for 8 × sin 56 if using heights; M1 for (their stated area / their areaABC) × 100 or (their height ADC / their height ABC) × 100; 45.7 to 45.71
Write your answer and get it marked
On Oracle Prep you can write or photograph your own answer and have it marked by AI against this mark scheme, with feedback on what you missed.
Sign up free →