Area — O/L Mathematics

What must I remember about Area?

• Area measures the extent of two-dimensional surface within a boundary: Rectangle Area = length × breadth (A = lb).
• Triangle Area = (1/2) × base × perpendicular height (A = 1/2 b h).
• Parallelogram Area = base × perpendicular height (A = b h); Trapezius Area = (1/2) × (sum of parallel sides) × perpendicular distance between them (A = 1/2 (a + b) h).
• Circle Area = πr²; Sector Area = (θ / 360) × πr².
• Compound shape area: Calculated either by additive composition (summing component sub-areas) or subtractive removal (subtracting unshaded hollows from enclosing outer geometry).

Test yourself (1 minute)

1. Perpendicular height requirement

   In triangles, parallelograms, and trapeziums, ALWAYS use the vertical perpendicular height (h), NEVER the slanted edge length.

2. Area units

   State final answers in square units (cm², m²); never write linear units (cm, m) for area.

3. Shaded area problems (Paper 1 & Paper 2)

   Clearly state the outer shape formula minus the inner cutout formula before substituting numerical values.

Practise Area questions today

Source: NIE G.C.E. (O/L) Mathematics Syllabus (Grade 10, Unit 6)

What should I study first?

What comes next?

Next in the syllabus

Where does Area fit in the syllabus?

Grade 10 · Term 1