Scalene Triangle Calculator

Calculate all properties of a scalene triangle: sides, angles, area, perimeter, and heights

Calculate Scalene Triangle

SSS: 3 sides | SAS: 2 sides + included angle | ASA: 2 angles + included side | AAS: 2 angles + any side

Triangle Properties

Enter triangle parameters to calculate properties

Example Calculation

Example: Scalene triangle with sides 3, 4, 5 cm

Given: a = 3 cm, b = 4 cm, c = 5 cm

Check if scalene: 3 ≠ 4 ≠ 5 ✓ (All sides different)

Triangle inequality: 3+4 > 5, 3+5 > 4, 4+5 > 3 ✓

Semi-perimeter: s = (3 + 4 + 5) / 2 = 6 cm

Area (Heron's): A = √[6×(6-3)×(6-4)×(6-5)] = √[6×3×2×1] = √36 = 6 cm²

Type: Right scalene triangle (3² + 4² = 5²)

Scalene Triangle Properties

All three sides have different lengths

All three angles are different

No lines of symmetry

No rotational symmetry

Can be acute, right, or obtuse

Formulas Used

Heron's Formula (Area)

A = √[s(s-a)(s-b)(s-c)]

where s = (a+b+c)/2

Law of Cosines

c² = a² + b² - 2ab⋅cos(C)

Law of Sines

a/sin(A) = b/sin(B) = c/sin(C)

Height Formula

h = 2A / base

Understanding Scalene Triangles

What Makes a Triangle Scalene?

A scalene triangle is the most general type of triangle where all three sides have different lengths. This also means all three angles are different. Most real-world triangles are scalene.

Key Characteristics

  • No equal sides (a ≠ b ≠ c)
  • No equal angles (A ≠ B ≠ C)
  • Irregular shape with no symmetry
  • Can be classified as acute, right, or obtuse

Calculation Methods

SSS (3 Sides)

Use Law of Cosines to find angles, then Heron's formula for area

SAS (2 Sides + Included Angle)

Use Law of Cosines for third side, then Law of Sines for remaining angles

ASA/AAS (Angles + Side)

Use Law of Sines to find missing sides and angles

Triangle Classification by Angles

Acute Scalene

All angles < 90°

Most common type

Right Scalene

One angle = 90°

Satisfies Pythagorean theorem

Obtuse Scalene

One angle > 90°

Largest angle is obtuse