Trapezoid Height Calculator

Calculate the height of a trapezoid using area, legs, and angles

Calculate Trapezoid Height

Method 1: Using Area and Bases

h = 2A / (a + b)

The height equals twice the area divided by the sum of both bases

Calculation Results

Enter the required values to calculate the trapezoid height

Please enter the area and both base lengths

Example Calculations

Method 1: Using Area and Bases

Given: Area = 64 cm², Base a = 21 cm, Base b = 19 cm

Formula: h = 2A / (a + b)

Calculation: h = (2 × 64) / (21 + 19) = 128 / 40 = 3.2 cm

Result: Height = 3.2 cm

Method 2: Using Leg and Angle

Given: Leg c = 10 cm, Angle α = 75°

Formula: h = c × sin(α)

Calculation: h = 10 × sin(75°) = 10 × 0.9659 = 9.659 cm

Result: Height = 9.659 cm

Method 3: Alternative Leg and Angle

Given: Leg d = 22 cm, Angle δ = 95°

Formula: h = d × sin(δ)

Calculation: h = 22 × sin(95°) = 22 × 0.9962 = 21.916 cm

Result: Height = 21.916 cm

Height Formulas

From Area & Bases

h = 2A / (a + b)

Where A is area, a and b are parallel bases

From Leg & Angle

h = c × sin(α)

Where c is leg, α is angle with base

Alternative Leg & Angle

h = d × sin(δ)

Where d is other leg, δ is its angle

Trapezoid Properties

Height is perpendicular distance between parallel bases

Height is constant across the entire trapezoid

Area = ½ × (sum of bases) × height

Legs are the non-parallel sides

Height can be found using trigonometry with legs

Quick Tips

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Choose method based on known values

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Area method requires both bases and area

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Trigonometric methods need one leg and angle

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Angles should be measured from leg to base

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All three methods give the same height

Understanding Trapezoid Height

What is Trapezoid Height?

The height of a trapezoid is the perpendicular distance between its two parallel sides (bases). This vertical distance remains constant across the entire width of the trapezoid.

Calculation Methods

  • Area Method: Use area and both base lengths
  • Trigonometric: Use a leg length and its angle with a base
  • Coordinate: Calculate using vertex coordinates

Formula Derivations

From Area Formula

Area = ½(a + b) × h

Rearranging: h = 2A / (a + b)

From Trigonometry

In right triangle formed by height:

h = leg × sin(angle)

Where angle is between leg and base

Applications

  • Architecture: Roof and foundation design
  • Engineering: Cross-sectional analysis
  • Land Surveying: Area calculations