Foundation November 2021 Paper 3 Q19
19 Here are a triangle and a rectangle.
Not drawn accurately
\(a\) and \(b\) are positive numbers.
Which shape has the larger perimeter?
You must work out expressions for both perimeters. [3 marks]
Tick a box.
- triangle
- rectangle
- cannot tell
| Answer | Mark | Comments |
|---|---|---|
| \(5a + b + 4a + 7b + 2a + 3b\) or \(2(4a + 2b) + 2(a + 4b)\) | M1 | oe |
| \(11a + 11b\) or \(10a + 12b\) | A1 | oe |
| \(11a + 11b\) and \(10a + 12b\) and cannot tell | A1 | oe with no further incorrect working |
Additional guidance
| Condone \(22ab\) after \(11a + 11b\) or \(10a + 12b\) for first A mark only | M1A1A0 |
| \(11a\) and \(11b\) or \(10a\) and \(12b\) implies M1 | M1A0 |
| \(5a + b = 6ab\) and \(4a + 7b = 11ab\) and \(2a + 3b = 5ab\) and \(6ab + 11ab + 5ab\) | M1A0 |
| \(6ab\) next to \(5a + b\) and \(11ab\) next to \(4a + 7b\) and \(5ab\) next to \(2a + 3b\) shown on diagram and \(6ab + 11ab + 5ab\) | M1A0 |
| \(5a + 4a + 2a = 15a\) and \(b + 7b + 3b = 12b\) and \(15a + 12b\) | M1A0 |