QR: Geometry, Area & Volume
Essential Formulas
You do NOT need to memorise complex geometry formulas. The UCAT tests basic shapes:
2D Shapes
- Rectangle: Area = length × width. Perimeter = 2(length + width)
- Triangle: Area = ½ × base × height
- Circle: Area = π × r². Circumference = 2π × r (use π ≈ 3.14)
- Trapezium: Area = ½ × (a + b) × h (where a and b are parallel sides)
3D Shapes
- Cuboid: Volume = length × width × height. Surface area = 2(lw + lh + wh)
- Cylinder: Volume = π × r² × h
- Sphere: Volume = (4/3) × π × r³
Common QR Geometry Questions
- Finding the area of a composite shape (e.g., L-shape = two rectangles, or rectangle with semicircle)
- Calculating how many tiles/units fit into a space
- Finding the volume of a container and relating it to a flow rate
- Converting between units of area (1 m² = 10,000 cm²) or volume (1 m³ = 1,000,000 cm³ = 1,000 litres)
- Scaling — if dimensions double, area quadruples and volume increases by factor of 8
Unit Conversion for Area and Volume
This is a common trap:
- 1 m = 100 cm, but 1 m² = 10,000 cm² (100²), and 1 m³ = 1,000,000 cm³ (100³)
- 1 km = 1000 m, but 1 km² = 1,000,000 m²
- 1 litre = 1000 cm³ = 0.001 m³