When to use this calculator
Recover a triangle’s perpendicular height from area and base. The returned altitude corresponds specifically to the entered base.
Explore the triangle calculators for other questions in this topic. For a related calculation, use the Triangle Area Calculator: Calculate a triangle’s area using a base and perpendicular height.
PUTTING IT INTO PRACTICE
Triangle Altitude: a worked example
The values below are an illustrative example, not a recommendation. Replace them with measurements or assumptions that match your question.
| Input | Example value |
|---|---|
| Triangle area | 30 |
| Chosen base | 10 |
| Result | 6 units |
- Check the input labels and enter the example values above.
- Apply the relationship: Perpendicular altitude = 2 × area/base.
- The result is 6 units, rounded for display.
How to interpret your result
The returned altitude corresponds specifically to the entered base.
Use base and perpendicular height for the simplest area calculation. With three known sides, Heron’s formula avoids measuring height. Triangle side lengths must satisfy the triangle inequality before any area result is meaningful.
Frequently asked questions
Can I use the sloping side as triangle height?
Only if it is perpendicular to the chosen base. A general sloping side is not the perpendicular height.
When is the triangle altitude calculator useful?
Recover a triangle’s perpendicular height from area and base. The returned altitude corresponds specifically to the entered base.
How do I use the triangle altitude calculator?
Enter triangle area, chosen base. The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Perpendicular altitude = 2 × area/base.
What should I check before using the result?
The returned altitude corresponds specifically to the entered base.
How are results rounded?
Scalar numbers display up to six decimal places, with scientific notation for very large or small values. Text, fraction, date and schedule outputs use the format described on the tool. Intermediate calculations use JavaScript floating-point arithmetic. Keep sensible precision for your measurements.
Further reading
For background on this topic, see OpenStax: non-right triangles ↗. This is a topic reference, not an external review or endorsement of this tool.
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