4MA0 Higher January 2015 Paper 3 Q9
9
(a) Find the sum of the interior angles of a polygon with 7 sides. (2)
Diagram NOT accurately drawn
The diagram shows a regular polygon with 7 sides.
(b) Work out the value of \(x\).
Give your answer correct to 1 decimal place. (2)
Give your answer correct to 1 decimal place. (2)
| Scheme | Marks |
|---|---|
(2 × 7 – 4) × 90 or (7 – 2) × 180 or \(7\left(180 - \dfrac{360}{7}\right)\) or 720 + 180 | M1 |
| 900 | A1 |
| (2) |
Notes
M1: For the sum of the interior angles or an interior angle
Eg Allow M1 for \(\dfrac{(7 - 2) \times 180}{7}\) oe
or 128.(571428.....) correctly rounded or truncated to at least 3SF.
A1: Mark the final answer
| Scheme | Marks |
|---|---|
| \(\tfrac{1}{2}\left(180 - \dfrac{900}{7}\right)\) or 0.5 × (360/7) or \(\dfrac{128.(571428\ldots)}{5}\) | M1ft |
| 25.7 | A1 |
| (2) | |
| (4 marks) |
Notes
M1ft: For a complete and correct method
A1: Accept 25.5 – 25.72
Allow \(\dfrac{180}{7}\) or \(25\frac{5}{7}\) oe