🎓 Mathematics • Geometry
100% Client-Side Privacy
Triangle Calculator
Solves Side-Side-Side (SSS) triangles: computes area via Heron’s formula, all 3 interior angles, and perimeter.
Geometry & Trigonometry Engine
Geometry, Area & Volume Studio
Solve triangles with Heron's formula and Law of Cosines, calculate circle sector arcs, compute 2D planar areas, 3D volumes, and exact Pythagorean radicals.
Three Side Lengths (SSS)
Preset Triangles:
ScaleneRight Triangle
Heron's Area6
Perimeter12
Angle α (opp a)36.87°
Angle β (opp b)53.13°
Angle γ (opp c)90°
What is Triangle Geometry?
A triangle is a three-sided polygon whose interior angles always sum to 180 degrees.
Triangles are rigid structures used in bridges, roofs, and 3D computer graphics meshes.
Formula & Step-by-Step Calculation
Area = √(s(s - a)(s - b)(s - c))
Heron’s formula calculates area directly from side lengths and semi-perimeter s.
Worked Step-by-Step Examples
Example 1
Area of triangle with sides 3, 4, 5
Solution: 6
• s = 6, Area = √(6×3×2×1) = 6
Common Real-World & Academic Use Cases
- ✓ Roof truss engineering
- ✓ Acreage boundary calculation
- ✓ Navigation triangulation
How to Use the Triangle Calculator
1
Enter Sides a, b, c
Input side lengths.
2
View Angles & Area
Inspect angles and surface area.
Frequently Asked Questions
Q: What is the Law of Cosines?
c² = a² + b² - 2ab cos(C), relating side lengths to opposite angles.