Foundation November 2018 Paper 3 Q18
18 The diagram shows a square, a regular hexagon and part of another regular polygon meeting at point P.
(a) Show that the size of one interior angle of a regular hexagon is 120°. [2]
(b) Find the number of sides of the other regular polygon. [4]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| 360 \(\div\) 6 = 60 | B1 | ||
| 180 – 60 [= 120] | B1 | Dep on first B1 scored Alternative method: M2 for \(\dfrac{180 \times (6 - 2)}{6} = 120\) M1 for attempt to use \(\dfrac{180(n - 2)}{n}\) | Accept 180 \(\times\) 4 as numerator Working must be seen May have incorrect \(n\) or contain numerical errors |
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| 12 | 4 | M3 for 360 \(\div\) 30 or M2 for 180 – (360 – 90 – 120) soi 30 or M1 for 360 – 90 – 120 soi 150 | Allow 120 – 90 or 120 + 90 – 180 May be on diagram |