Triangle Slope Calculator

Calculate slopes using triangle method or find the slope of a triangle itself

Slope Calculation

Triangle Slope Results

Enter the required values to calculate triangle slope

Slope Calculation Examples

Triangle Slope - Using Sides

Given: Rise (a) = 3, Run (b) = 4

Formula: slope = rise/run = a/b

Calculation: slope = 3/4 = 0.75

Result: Slope = 0.75, Angle = 36.87°, Grade = 75%

Triangle Slope - Using Angle

Given: Angle α = 30°

Formula: slope = tan(α)

Calculation: slope = tan(30°) = 0.577

Result: Slope = 0.577, Grade = 57.7%

Line Slope - Using Points

Given: Point 1 (1, 2), Point 2 (5, 8)

Formula: slope = (y₂ - y₁)/(x₂ - x₁)

Calculation: slope = (8 - 2)/(5 - 1) = 6/4 = 1.5

Result: Slope = 1.5, Rise = 6, Run = 4

Slope Calculation Methods

1

Rise over Run

slope = rise/run = a/b

2

Tangent of Angle

slope = tan(α)

3

Cotangent of Angle

slope = cot(β) = 1/tan(β)

Slope Properties

Positive Slope

Line rises from left to right

Negative Slope

Line falls from left to right

Zero Slope

Horizontal line

Undefined Slope

Vertical line

Quick Tips

Rise is the vertical change (up/down)

Run is the horizontal change (left/right)

Slope = tan(angle) for right triangles

Steeper slopes have larger absolute values

Understanding Triangle Slope

What is a Slope Triangle?

A slope triangle is a right triangle formed by drawing horizontal and vertical lines from two points on a line. This creates a visual representation that helps calculate the slope using the rise over run formula.

Triangle Slope Methods

  • Sides Method: Use rise/run = a/b where a is vertical side, b is horizontal side
  • Angle α Method: Use slope = tan(α) where α is angle at horizontal side
  • Angle β Method: Use slope = cot(β) where β is angle at vertical side

Mathematical Formulas

Basic Slope Formula

slope = rise/run = (y₂ - y₁)/(x₂ - x₁)

Triangle Slope Formula

slope = a/b = tan(α) = cot(β)

Angle Conversion

angle = arctan(slope) × 180/π

Applications

  • • Surveying and construction
  • • Road grade calculations
  • • Roof pitch determination
  • • Physics and engineering