Rhombus: side and area give the diagonals via (d1 ± d2)^2

CAT has tested this idea 3 times across 3 papers, from 2021 to 2025. Solve one, and the others are the same method with different numbers or wording, which is why repeated concepts are the most efficient thing to practise.

Question	What it asks	Answer
CAT 2025 Slot 1 · QA Q15 near-repeat	side 36, area 396; difference of diagonals	60
CAT 2021 Slot 2 · QA Q9 near-repeat	side 5, area 12; longer diagonal	C
CAT 2021 Slot 3 · QA Q12 near-repeat	perimeter 40, area 96; sum of diagonals	3500

Part of Geometry (65 questions since 2017).