Triangle Calculator
Calculate area, perimeter, and angles of a triangle given its side lengths.
Enter the lengths of the three sides of the triangle.
About this Tool
The Triangle Calculator is a comprehensive tool that solves for the area, perimeter, and angles of a triangle when given the lengths of all three sides. It uses Heron's formula to find the area and the Law of Cosines to determine the angles.
Common Use Cases
Geometry Homework
Quickly solve for all properties of a triangle for math assignments.
Construction and DIY
Calculate angles and area for projects that involve triangular shapes, such as building a truss or cutting a piece of land.
Land Surveying
Estimate the area and angles of a triangular plot of land from its side measurements.
Pro Tips
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Triangle Inequality Theorem
For any three lengths to form a valid triangle, the sum of the lengths of any two sides must be greater than the length of the third side.
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Units
Ensure all side lengths are in the same unit. The area will be in square units, and the perimeter will be in linear units.
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Angle Sum
The sum of the three angles in any triangle always equals 180 degrees. You can use this to check your results.