Intermediate November 2021 Unit 2 Q6
6. ABCD and PQRS are both squares.
AB = 9 cm.
Shaded area = 32 cm2.
Calculate the length of PQ. [4]

Diagram not drawn to scale
| Scheme | Marks | Comments |
|---|---|---|
| Correct strategy of √(Area ABCD – 32) | S1 | |
| (Area ABCD =) 81 (cm2) | B1 | |
| (Area PQRS = 81 – 32 =) 49 (cm2) | B1 | FT ‘their stated area of ABCD’ – 32. |
| (PQ = √49 =) 7 (cm) | B1 | FT √’their stated area of PQRS’ but not √32 or √9 A final answer of 7(cm) gains all four marks. May be seen on the diagram. (FT answers must be rounded or truncated to 1dp or more) |