Mathematics · Geometry
Triangle Area Calculator
Calculate triangle area from a base and perpendicular height.
Inputs and results stay in this browser. Change one value at a time to explore the relationship.
Calculation steps
- Multiply base and height: 12 × 7 = 84.
- Take half: 84 ÷ 2 = 42.
Definition and formula
A triangle with a given base and perpendicular height has half the area of the corresponding parallelogram.
Area = ½ × base × height
Worked example
A triangle with base 12 and height 7 has area 42.
Common mistake
The height must be perpendicular to the selected base.
How to learn with this calculator
Begin with the worked example, then change one value while keeping the others fixed. Compare the new result and calculation steps to identify which part of the formula changed.
Clear answers
Frequently asked questions
What does the Triangle area do?
Calculate triangle area from a base and perpendicular height.
How does the Triangle area work?
The calculator applies Area = ½ × base × height. A triangle with a given base and perpendicular height has half the area of the corresponding parallelogram.
What can I learn from the Triangle area?
It connects the mathematical rule to your chosen numbers and shows each calculation step. Change one input at a time to see how the result responds.
Does MW SysArc receive or store what I enter?
No. The calculation runs locally in your browser. MW SysArc does not receive or store your calculation inputs.
How should I use the result?
Use the steps to understand the method, then verify important school or professional work using the notation and rounding rules required in your setting.
Last reviewed 2026-07-14. Calculations tested 2026-07-14.