Parallelogram Calculator

Calculate area, perimeter & diagonal of any parallelogram instantly

Calculation Results

Enter parallelogram measurements to calculate properties.

Base (b): units

Height (h): units

Area (A): square units

Perimeter (P): units

Diagonal (d): units

Side (s): units

Angle (α): °

Angle (β): °

Parallelogram Diagram

h b s d α

The Parallelogram: A Versatile Geometric Shape

A parallelogram is a four-sided polygon (a quadrilateral) where opposite sides are parallel and equal in length. The opposite angles are also equal, and adjacent angles are supplementary.

Key Properties of a Parallelogram

  • Base (b) - One of the sides used as the reference for height.
  • Height (h) - The perpendicular distance from the base to the opposite side.
  • Area (A) - The space enclosed within the parallelogram (A = b × h).
  • Perimeter (P) - Total distance around the shape (P = 2(a + b) where a and b are adjacent sides).
  • Diagonals - Parallelograms have two diagonals that bisect each other but are not necessarily equal.
  • Angles - Opposite angles are equal, and adjacent angles add up to 180°.

Mathematical Equations of a Parallelogram

  • Area
    A = b × h
  • Perimeter
    P = 2(a + b)
  • Diagonal 1 (d₁)
    d₁ = √(a² + b² + 2ab cosθ)
  • Diagonal 2 (d₂)
    d₂ = √(a² + b² - 2ab cosθ)

Why Are Parallelograms Important?

  • Engineering - Parallelogram linkages are used in mechanical arms and devices.
  • Architecture - Parallelogram shapes appear in trusses and beams.
  • Mathematics - A key figure in vector geometry and linear algebra.
  • Art & Design - Frequently used in tiling patterns and perspective drawing.

Facts About Parallelograms

  • The word "parallelogram" comes from the Greek "parallelogrammon", meaning "bounded by parallel lines".
  • A square, rectangle, and rhombus are all special types of parallelograms.
  • The diagonals of a parallelogram always bisect each other.

Parallelograms blend simplicity with versatility. Their symmetrical structure and mathematical properties make them vital in geometry, physics, design, and more.

Parallelogram Formulas

  • Area (A): A = b × h
  • Area (A):
    Using two adjacent sides and included angle:
    A = ab · sin(θ)
  • Perimeter (P): P = 2(a + b)
  • Height (h): h = A / b
  • Base (b): b = A / h
  • Diagonal (d₁/d₂): d = √(a² + b² ± 2ab cosθ)
b

Base (b)

h

Height (h)

A

Area (A)

d

Diagonal

How to Use the Parallelogram Calculator

This Parallelogram Calculator helps compute area, perimeter, height, or side lengths depending on the known values.

1 Select the Input Type

Choose what you know:

  • Base and height
  • Area and base
  • Area and Height
  • Perimeter and Base
  • Base, Side & included Angle (θ)

Example: If you know base = 10 and height = 5, choose those inputs.

2 Enter the Known Value(s)

Enter numeric values in the fields.

  • Use only positive values.
  • Use decimals if needed (e.g., 7.5).

Example: Base = 8, Height = 4

3 Click "Calculate"

The calculator will display:

  • Area
  • Perimeter
  • Diagonal (if angle is given)

Example Use Cases

  • Calculating floor space in slanted structures like attics.
  • Determining beam length in roof trusses.
  • Finding the angle between sides using diagonals.

Example Calculations

  • Example 1: Base = 10 units, Height = 6 units

    • Area = 60 units²
    • Perimeter = (2 × (10 + 6)) = 32 units
  • Example 2: Area = 72 units², Base = 12 units

    • Height = 6 units
    • Perimeter requires side info
  • Example 3: Sides a = 8, b = 6, θ = 60°

    • Diagonal ≈ 11.66 units (using cosine formula)

Frequently Asked Questions

1. How is the area of a parallelogram calculated?

Use the formula:

A = b × h

2. Is every parallelogram a rectangle?

No. While all rectangles are parallelograms, not all parallelograms have right angles, which is required for rectangles.

3. Do diagonals of a parallelogram bisect each other?

Yes, the diagonals always bisect each other but are not generally equal in length.

4. Where are parallelograms used in real life?
  • Physics: Force diagrams
  • Engineering: Parallelogram linkages
  • Design: Tiling, weaving patterns
  • Graphics: 3D transformations and perspective