Area of a Trapezium Formula Explained, With Examples
Every area of a trapezium result comes from one formula. Once you understand what goes into it, you can sanity-check any figure you are given, whether by an employer, a bank, a teacher or another website.
The formula
½(a + b) × h
What each input means
- Parallel side a: the value you enter in the calculator.
- Parallel side b: the value you enter in the calculator.
- Height: the value you enter in the calculator.
Example
For example, with these inputs:
- Parallel side a: 6
- Parallel side b: 10
- Height: 4
the calculator returns:
- Area: 32
How the result changes
The table keeps the other inputs at their example values and changes parallel side a.
| Parallel side a | Area |
|---|---|
| 6 | 32 |
| 3 | 26 |
| 4.5 | 29 |
| 7.5 | 35 |
| 9 | 38 |
Why it matters
These calculations come up in school, at work and in daily life, from PSLE and O-Level practice to measuring a room for new flooring. Doing them by hand builds understanding, and a calculator lets you check the answer instantly.
These calculations appear throughout the Singapore syllabus, from primary school percentages and fractions to secondary school algebra and geometry. Understanding the formula makes problem sums easier because you can recognise which quantity is missing.
Each formula has assumptions built in. Area formulas assume flat shapes, volume formulas assume regular solids and statistical measures assume the data you enter is the data you want to describe. Knowing the assumptions helps you pick the right tool.
Calculators are best used to check working rather than replace it, especially for exams where method marks count. Work the problem by hand first, then confirm with the calculator.
Related calculations
- Decimal to Fraction Converter: Converts a decimal to a fraction.
- Scientific Notation Converter: Writes a number in scientific notation.
- Rounding Calculator: Rounds a number to the decimal places you choose.
- Prime Number Checker: Checks whether a number is prime.
Use the Area of a Trapezium Calculator to plug in your own numbers.
Run your own numbers: Area of a Trapezium Calculator