Higher November 2018 Paper 2 Q10
10. The perimeter of the rectangle shown below is 232·8 cm.
Diagram not drawn to scale
Form an equation in terms of \(x\) and solve it.
Hence find the dimensions of the rectangle. [5]
| Scheme | Marks | Comments |
|---|---|---|
| \(3(7x+5)+2x-9+3(7x+5)+2x-9=232.8\) | B1 | Or equivalent |
| \(21x+15+2x-9+21x+15+2x-9=232.8\) | B1 | FT from ‘\(21x+15+2x-9=232.8\)’ (semi perimeter) |
| \(46x + 12 = 232.8\) or \(46x = 220.8\) or \(x = 220.8 \div 46\) | B1 | FT from 1 error (or repeated error) in multiplying out brackets |
| \(x = 4.8\) (cm) | B1 | FT from ‘their \(ax + b = 232.8\)’ provided \(a \ne 0\) and \(b \ne 0\) (FT from semi perimeter is 9.86... cm) |
| Length 115.8 (cm) AND Width 0.6 (cm) | B1 | (FT from semi perimeter is 222.06 cm AND 10.72 cm) FT evaluations correct for ‘their derived x’ |
| (5) |