Triangle Calculator - Free Online Geometry Tool
Advanced triangle calculator with comprehensive geometry calculations including area, perimeter, angles, heights, medians, inradius, and circumradius. Supports all triangle solving methods: SSS, SAS, ASA, AAS, and SSA.
Triangle Calculator
Advanced triangle calculations with all properties
Sides
Angles
Instructions:
Provide 3 values including at least one side. When radians are selected, angles can be entered as π/2, π/4, etc.
How to Use Triangle Calculator
Our advanced triangle calculator supports all major triangle solving methods:
- SSS (Side-Side-Side): Provide all three sides to calculate angles and area
- SAS (Side-Angle-Side): Provide two sides and the included angle
- ASA (Angle-Side-Angle): Provide two angles and the included side
- AAS (Angle-Angle-Side): Provide two angles and a non-included side
- SSA (Side-Side-Angle): Provide two sides and a non-included angle
Simply enter your known values and click "Calculate" to get comprehensive triangle properties including area, perimeter, angles, heights, medians, inradius, and circumradius.
Triangle Types & Properties
By Sides:
- Equilateral: All three sides equal
- Isosceles: Two sides equal
- Scalene: All sides different lengths
By Angles:
- Acute: All angles less than 90°
- Right: One angle exactly 90°
- Obtuse: One angle greater than 90°
Key Mathematical Formulas
Area Formulas:
- Heron's Formula: A = √[s(s-a)(s-b)(s-c)] where s = (a+b+c)/2
- Base × Height: A = ½ × base × height
- SAS Formula: A = ½ × a × b × sin(C)
Angle Formulas:
- Law of Cosines: c² = a² + b² - 2ab cos(C)
- Law of Sines: a/sin(A) = b/sin(B) = c/sin(C)
- Angle Sum: A + B + C = 180°
Frequently Asked Questions
What triangle solving methods are supported?
Our calculator supports all major triangle solving methods: SSS (Side-Side-Side), SAS (Side-Angle-Side), ASA (Angle-Side-Angle), AAS (Angle-Angle-Side), and SSA (Side-Side-Angle). Simply provide any 3 values including at least one side.
Can I use radians instead of degrees?
Yes! You can switch between degrees and radians using the angle unit selector. When radians are selected, you can enter angles as π/2, π/4, etc.
What additional properties does the calculator provide?
Beyond basic area and perimeter, our calculator provides heights, medians, inradius, circumradius, triangle type classification, and comprehensive geometric properties for complete triangle analysis.