Area of a Trapezoid Calculator

Calculate the area, perimeter, and properties of trapezoids using parallel bases and height

Calculate Trapezoid Properties

One of the parallel sides

cm

The other parallel side

cm

Perpendicular distance between parallel bases

a = 0b = 0h = 0

Trapezoid Properties

0.00
Area (cm²)
0.00
Median (cm)

Formulas Used:

Area: A = (a + b) × h / 2

Median: m = (a + b) / 2

Calculation: (0 + 0) × 0 / 2

Example Calculation

Garden Bed Trapezoid

Given: Base A = 8 meters, Base B = 4 meters, Height = 5 meters

Find: Area and median of the trapezoid

Solution

Area: A = (a + b) × h / 2 = (8 + 4) × 5 / 2 = 30 m²

Median: m = (a + b) / 2 = (8 + 4) / 2 = 6 m

Result: The trapezoid has an area of 30 square meters

Trapezoid Formulas

Area

A = (a + b) × h / 2

Where a, b are parallel bases and h is height

Perimeter

P = a + b + c + d

Sum of all four sides

Median (Midsegment)

m = (a + b) / 2

Average of parallel bases

Trapezoid Properties

Has exactly one pair of parallel sides (bases)

Sum of interior angles equals 360°

Adjacent angles are supplementary (sum to 180°)

Median connects midpoints of non-parallel sides

Median is parallel to bases and equals their average

Understanding Trapezoids and Area Calculation

What is a Trapezoid?

A trapezoid is a quadrilateral (4-sided polygon) with exactly one pair of parallel sides called bases. The non-parallel sides are called legs. The perpendicular distance between the parallel bases is the height.

Key Components

  • Bases (a, b): The two parallel sides
  • Legs (c, d): The two non-parallel sides
  • Height (h): Perpendicular distance between bases
  • Median: Line segment connecting midpoints of legs

Area Formula Derivation

The trapezoid area formula comes from the average of the two parallel bases multiplied by the height:

A = (a + b) × h / 2

This can be understood as the area of a rectangle with width equal to the average of the bases: (a + b)/2, and height h.

Special Case: When a = b, the trapezoid becomes a rectangle, and the formula simplifies to A = a × h.

Types of Trapezoids

Scalene Trapezoid

All sides have different lengths. No special symmetry properties.

Isosceles Trapezoid

Both legs have equal length. Has line symmetry and equal base angles.

Right Trapezoid

Has two adjacent right angles. One leg is perpendicular to both bases.