Triangle Solver (SSS)
Enter 3 sides to visually solve the triangle. Calculate Angles, Area, and Perimeter instantly.
Geometry made easy. Enter the lengths of three sides, and our **Triangle Solver** will instantly build the triangle and calculate all its unknown angles and area.
Side Lengths
Triangle Visualizer
Calculated Properties
What is Triangle Solver (SSS)?
Solving Triangles (SSS)
SSS stands for **Side-Side-Side**. It is a congruence postulate that states if you know the lengths of all three sides of a triangle, the triangle is uniquely determined (its shape and size are fixed).
Using the Law of Cosines, we can then determine all interior angles.
Formula & Calculation
Law of Cosines
Used to find angles when sides are known:
c² = a² + b² - 2ab cos(C)Heron's Formula (Area)
Area = √{s(s-a)(s-b)(s-c)}where 's' is semi-perimeter: (a+b+c)/2
Example Calculation
The 3-4-5 Triangle
A classic Right-Angled Triangle.
- Inputs: a=3, b=4, c=5
- Result: Angle C will be exactly 90°.
- Area: 6 square units.
Try entering 3, 4, and 5 above to verify!
Frequently Asked Questions
What happens if sides are too short?
The Triangle Inequality Theorem states that the sum of any two sides must be greater than the third side ($a+b \gt c$). If not, the sides can't touch to form a closed shape.