Foundation November 2018 Paper 1 Q21
21.
Diagram not drawn to scale
The diagram shows two similar, right-angled triangles, PQR and ABC.
Find the value of \(x\). [4]
| Scheme | Marks | Comments |
|---|---|---|
| (BC =) 5 | B1 | |
| \(12^2 + 5^2\) (= 169) | M1 | FT ‘their 5’ |
| \(x^2 = 169\) or \(x = \sqrt{169}\) | A1 | FT ‘their 5’ |
| (\(x\) = ) 13 | A1 | FT from M1, if possible, for the correctly evaluated square root of ‘their 169’ provided ‘their answer’ > 12. Accept an unsupported 13 (cm) If no marks award SC1 for sight of AC = ½ × PR or equivalent |
| (4) |
Alternative
Alternative method
| Scheme | Marks | Comments |
|---|---|---|
| \(24^2 + 10^2\) (= 676) | M1 | |
| \(x^2 = 676\) or \(x = \sqrt{676}\) | A1 | |
| (PR = ) 26 | A1 | |
| (\(x\) = ) 13 | B1 |