Triangle Calculator
Calculate area, perimeter and angles of a triangle. With side lengths or angles.
Enter at least three values (e.g. three sides or two sides and one angle).
Result
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Note: These calculations are for informational purposes only and do not replace professional tax or financial advice. All information without guarantee.
Frequently Asked Questions
How do I calculate the area of a triangle?
Area equals base times height divided by 2. Alternatively, use Heron's formula with three sides: Area equals the square root of s(s-a)(s-b)(s-c), where s is the semi-perimeter.
What is the Pythagorean theorem?
In a right triangle, the square of the hypotenuse equals the sum of the squares of the other two sides: a squared plus b squared equals c squared. Only valid for right triangles.
What is the Triangle Calculator?
The triangle calculator computes sides, angles, area, perimeter and heights of a triangle from the given values.
How does the Triangle Calculator work?
Enter at least three values (e.g. 3 sides or 2 sides + 1 angle). The calculator computes all missing values using the sine rule, cosine rule and area formulas. For right triangles the Pythagorean theorem is applied.
Key Data and Facts
Area formula: A = 0.5 * base * height. Pythagoras: a squared + b squared = c squared. Sum of interior angles: always 180 degrees. Cosine rule: c squared = a squared + b squared - 2ab * cos(C).
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