Foundation June 2024 Paper 3 Q18
18 The diagram shows two straight lines AB and DC that intersect at P.
DA is parallel to BC.
Complete these statements to show that triangle PAD is similar to triangle PBC.
Angle ADP = angle BCP because they are alternate angles
Angle APD = angle ................ because they are ................................ angles
Angle ................ = angle ................ because they are ................................ angles
Triangle PAD is similar to triangle PBC because ................................................ [4]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| BPC or CPB and [vertically] opposite | B2 | B1 for BPC or CPB | Must use 3-letter notation |
| DAP or PAD, CBP or PBC, alternate | B1 | Must have angle and reason | Condone • A and B if clear for e.g. A for PAD and B for CBP • Changed order e.g. CBP and PAD • Use of B or C for P e.g. DAB for DAP For reason, condone poor spelling (alternative) and accept “third angle in triangle” oe |
| AAA oe | B1dep | Dependent on previous B2 and B1 | Accept completely correct statements e.g. “All corresponding angles equal” but not “All angles equal” or “They have the same angles” See Appendix |
Appendix
Appendix Question 18
| Reason | Mark | Reason |
|---|---|---|
| Corresponding [pairs of] angles are equal | 1 | |
| Matching angles in the triangles are equal | 1 | |
| They have the same angles | 0 | Not specific enough |
| All angles equal | 0 | Not true |