Higher November 2024 Paper 2 Q16
16 \(A\), \(B\), \(C\) and \(D\) are points on a circle, centre \(O\)

Diagram NOT accurately drawn
(a)
(i) Work out the size of angle \(AOD\) (1)
(ii) Give a reason for your answer to part (a)(i) (1)
(b) Work out the size of angle \(CAO\) (1)
(c) Work out the size of angle \(ABC\) (2)
| Scheme | Marks |
|---|---|
| (i) Answer: 108 | B1 |
| (1) | |
| (ii) Answer: Correct reason | B1 |
| (1) |
Notes
B1: Accept 252
B1: dep on (a)(i) correct
Angle at the centre(midpoint/origin/middle)is twice the angle at the circumference(side/edge/arc) oe
Inscribed angle is half of the central angle oe
(accept ∠ for ‘angle’ and 2 × or double for twice)
| Scheme | Marks |
|---|---|
| 26 | B1 |
| (1) |
| Scheme | Marks |
|---|---|
| \(ABC = 180 - \text{``}{64}\text{''}\) or \(\dfrac{\text{``}{108}\text{''} + \text{``}{124}\text{''}}{2}\) | M1ft |
| Correct answer scores full marks (unless from obvious incorrect working) Answer: 116 | A1 |
| (2) | |
| (5 marks) |
Notes
M1ft: follow through their (½(180 – “108”)) in 28 + “36”= 64
ONLY FOLLOW THROUGH THEIR 108
A1: cao