Foundation June 2025 Paper 3 Q16
16 Here is an equilateral triangle.
All measurements are in centimetres.
Not drawn accurately
Work out the value of the perimeter of the triangle. [4 marks]
| Answer | Mark | Comments |
|---|---|---|
| \(6x - 8 = 2x + 12\) | M1 | oe equation in terms of \(x\) any letter |
| \(6x - 2x = 12 + 8\) or \(-8 - 12 = 2x - 6x\) or \(4x = 20\) or \((x =)\ 5\) | M1dep | oe collection of terms eg \(4x - 20 = 0\) |
| \(6 \times\) their \(5 - 8\) or \(2 \times\) their \(5 + 12\) or 22 | M1dep | a combination of sides may be used eg \(14 \times 5 - 4\) or \(10 \times 5 + 16\) |
| 66 | A1 |
Additional guidance
| 5 or 22 may be shown on diagram | |
| Trial and improvement with 22 selected as length of side | M3 |
| Trial and improvement with 5 selected as value of \(x\) | M2 |
| \(8x + 4 = 180\) and \(x = 22\) | M0 |