Foundation June 2019 Paper 1 Q14
14.
Diagram not drawn to scale
Show that \(x = 50^\circ\).
Give a reason for each step of your answer. [4]
| Scheme | Marks | Comments |
|---|---|---|
| TRS or TSR = 40° (Base angles of an isosceles triangle (are equal)) | B1 | Answers may be seen on the diagram If values not marked on diagram, angle labels must be correct; allow S =…. or R = …. |
| PTQ = 40° (Corresponding angles (are equal)) or QTR = 40° (Alternate angles (are equal)) and PTQ = 40° (Angles on a straight line (sum to 180)) | B1 | FT ‘their TRS or TSR’; if values not marked on diagram, angle labels must be correct; do not allow T = ….. |
| (\(x\) = ) 90° – 40° = 50° (QTU is a right angle) | B1 | CAO as answer given; must be convinced they are not working back from the given value and full and correct method must be shown |
| At least one correct reason stated appropriately | E1 | |
| (4) |
Alternative
Alternative method:
| Scheme | Marks | Comments |
|---|---|---|
| Draws the line of symmetry, TM, of triangle RTS and MTS = 50° (TM is a line of symmetry or triangles RTM and STM are congruent or equivalent) | B2 | |
| (\(x\) = ) 50° (Vertically) opposite angles | B2 |