Higher November 2020 Paper 2 Q7
7. Cheng stands at \(O\) and rolls a ball along the horizontal ground.
The ball stops at point \(B\), which:
- is equidistant from \(X\) and \(Y\),
- lies on the bisector of angle \(XOY\).
Use a ruler and a pair of compasses to construct suitable lines and arcs to show the position of point \(B\).
Construction arcs must be clearly shown. [5]
| Scheme | Marks | Comments |
|---|---|---|
| Correct perpendicular bisector construction with appropriate arcs | B2 | B1 for perpendicular bisector within tolerance (± 2°) without arcs or with invalid arcs or for correct pair of arcs that intersect twice |
| Correct angle bisector construction of \(XOY\) with appropriate arcs | B2 | B1 for angle bisector within tolerance (± 2°) without arcs or with invalid arcs or for a correct pair of arcs |
| Correct point indicated | B1 | FT provided at least B1, B1 awarded; may be implied by intersecting loci |
| (5) |