Area of a Triangle Formula Explained, With Examples
Every area of a triangle 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 × base × height
What each input means
- Base: the value you enter in the calculator.
- Height: the value you enter in the calculator.
Example
For example, with these inputs:
- Base: 10
- Height: 6
the calculator returns:
- Area: 30
How the result changes
The table keeps the other inputs at their example values and changes base.
| Base | Area |
|---|---|
| 10 | 30 |
| 5 | 15 |
| 7.5 | 22.5 |
| 12.5 | 37.5 |
| 15 | 45 |
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.
Rounding is a common source of small errors. Keep full precision during intermediate steps and round only the final answer to the number of decimal places or significant figures the question asks for.
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
- Quadratic Equation Solver: Solves ax² + bx + c = 0.
- Pythagorean Theorem Calculator: Finds the hypotenuse of a right triangle.
- Fraction Simplifier: Reduces a fraction to its lowest terms.
- Ratio Simplifier: Simplifies a ratio.
Use the Area of a Triangle Calculator to plug in your own numbers.
Run your own numbers: Area of a Triangle Calculator