Triangle Area Calculator
Compute the area of a triangle: A = ½ × base × height.
Calculator
Use the Triangle Area Calculator
Result
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Formula
A = ½ × base × height
Step-by-step
- 1
Enter base and height
Height is perpendicular to the base.
- 2
Read the area
Area in square units.
Worked example
Example input: a: 10, b: 6
Result: 30
Related tools
- Pythagorean Theorem
Right-triangle hypotenuse.
Frequently asked questions
How do you find the area of a triangle?
Multiply the base by the perpendicular height and halve it: A = ½ × base × height. A base of 10 with a height of 6 gives an area of 30 square units.
Does the height need to be perpendicular?
Yes — the height is the perpendicular distance from the base to the opposite vertex, not just any side length. In a right triangle, one leg serves as the height when the other leg is the base.
What if I only know the three side lengths?
This calculator works from base and height. For a right triangle, use the Pythagorean Theorem calculator to connect the sides first; with three arbitrary sides you need an angle or a construction of the perpendicular before the area follows.