4MA0 Higher June 2013 Paper 4 Q13
13 The diagram shows an incomplete regular polygon.
Diagram NOT accurately drawn
The size of each interior angle is 140 degrees greater than the size of each exterior angle.
Work out the number of sides the regular polygon has.
(4)
| Scheme | Marks |
|---|---|
| 20 or 160 | M1 |
| A1 | |
| 360 ÷ “20” or 720 ÷ “40” | M1 |
| 18 | A1 |
| (4) |
Notes
M1: M1 for \((140 + x) + x = 180\) oe or \(y + (y - 140) = 180\) or \(\dfrac{180(n-2)}{n} - 140 = \dfrac{360}{n}\)
A1: \(x = 20\) or \(y = 160\) or \(180n - 140n = 720\)
M1: dep on previous M1