Higher November 2017 Paper 1 Q14
14 Two congruent regular polygons are joined together.
Not drawn accurately
Work out the number of sides on each polygon. [3 marks]
| Answer | Mark | Comments |
|---|---|---|
| Alternative method 1 | ||
| \(60 \div 2\) or 30 | M1 | exterior angle may be on diagram |
| \(360 \div\) their 30 | M1dep | |
| 12 | A1 | |
| Alternative method 2 | ||
| \(\dfrac{360 - 60}{2}\) or \(\dfrac{300}{2}\) or 150 | M1 | interior angle may be on diagram |
| \(360 \div (180 -\) their 150) or \(360 \div 30\) | M1dep | |
| 12 | A1 | |
| Alternative method 3 | ||
| \(\dfrac{360 - 60}{2}\) or \(\dfrac{300}{2}\) or 150 | M1 | interior angle may be on diagram |
| \(180 \times (n - 2) =\) their \(150 \times n\) or \(180n -\) their \(150n = 360\) or \(30n = 360\) | M1dep | oe equation |
| 12 | A1 | |