Rhombus Calculator

Calculate area, perimeter, diagonals, and angles of any rhombus

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All sides of a rhombus are equal

The other diagonal will be calculated

Diagonals of a rhombus bisect each other at 90°

Any interior angle of the rhombus (opposite angles are equal)

Rhombus Properties

Area

Perimeter

Side Length

Height

Diagonal d₁ (longer)

Diagonal d₂ (shorter)

Acute Angle

°

Opposite angles are equal

Obtuse Angle

°

Adjacent angles sum to 180°

Rhombus Properties

All 4 sides are equal
Diagonals intersect at 90°
Diagonals bisect each other
Opposite angles are equal

Rhombus Formulas

Area (from diagonals)

A = (d₁ × d₂) / 2

Perimeter

P = 4a

Area (from angle)

A = a² × sin(θ)

Diagonal Relationship

d₁² + d₂² = 4a²

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About Rhombus Calculator

What is a Rhombus?

A rhombus is a special type of parallelogram where all four sides are equal in length. It is also known as a diamond or lozenge shape. The opposite angles of a rhombus are equal, and adjacent angles are supplementary (add up to 180°).

Rhombuses are commonly found in playing card suits (diamonds), kites, jewelry designs, and various architectural patterns.

Key Properties of a Rhombus

All Sides are Equal

The defining characteristic of a rhombus is that all four sides have the same length. This distinguishes it from a general parallelogram.

Diagonals Bisect Each Other at Right Angles

Unlike a general parallelogram, the diagonals of a rhombus intersect at 90° angles. They also bisect each other (cut each other in half).

Diagonals Bisect the Angles

Each diagonal divides the corner angles into two equal parts.

Opposite Angles are Equal

Like all parallelograms, opposite angles in a rhombus are equal.

How to Use This Calculator

From Side & Diagonal Mode

  1. Select Side & Diagonal mode
  2. Enter the side length (a)
  3. Enter one diagonal length (d₁)
  4. The calculator computes the other diagonal, area, perimeter, height, and angles

From Diagonals Mode

  1. Select Diagonals mode
  2. Enter both diagonal lengths (d₁ and d₂)
  3. The calculator derives side length, area, perimeter, and angles

From Side & Angle Mode

  1. Select Side & Angle mode
  2. Enter the side length (a)
  3. Enter an interior angle (in degrees)
  4. Get complete rhombus measurements including diagonals and height

Rhombus Formulas

Core Formulas

Property Formula Description
Area (from diagonals) A = (d₁ × d₂) / 2 Half the product of diagonals
Area (from side × height) A = a × h Side times perpendicular height
Area (from side × sin) A = a² × sin(θ) Side squared times sine of angle
Perimeter P = 4a Four times the side length
Height h = A / a Area divided by side

Diagonal Formulas

| Property | Formula | |----------|---------|| | Diagonal from side & angle | d₁ = a × √(2 + 2cos(θ)) | | Diagonal from side & angle | d₂ = a × √(2 - 2cos(θ)) | | Side from diagonals | a = √((d₁/2)² + (d₂/2)²) | | Diagonal relationship | d₁² + d₂² = 4a² |

Angle Formulas

| Property | Formula | |----------|---------|| | Adjacent angles | θ₁ + θ₂ = 180° | | Angle from diagonals | θ = 2 × arctan(d₂/d₁) |

Rhombus vs Other Quadrilaterals

Rhombus vs Parallelogram

A rhombus is a special parallelogram where all sides are equal. In a general parallelogram, only opposite sides are equal.

Rhombus vs Square

A square is a special rhombus where all angles are 90°. A rhombus can have any angle configuration as long as opposite angles are equal.

Rhombus vs Kite

Both have perpendicular diagonals, but a kite has two pairs of adjacent equal sides, while a rhombus has all four sides equal.

Real-World Applications

Design & Art

  • Diamond patterns in textiles and wallpaper
  • Playing card suit symbols
  • Jewelry and gemstone cuts
  • Tile and mosaic patterns

Architecture

  • Window designs
  • Decorative elements
  • Floor patterns

Engineering

  • Mechanical linkages
  • Structural analysis
  • Folding mechanisms

Frequently Asked Questions

Is a square a rhombus?

Yes! A square is a special type of rhombus where all angles are exactly 90°. Every square is a rhombus, but not every rhombus is a square.

Why do the diagonals of a rhombus intersect at 90°?

This is a unique property of rhombuses (and squares). Because all sides are equal, the triangles formed by the diagonals are congruent, which forces the diagonals to meet at right angles.

How is a rhombus different from a diamond?

"Diamond" is often used as an informal name for a rhombus, especially when referring to the shape oriented so that one diagonal is vertical (like a playing card diamond suit).

Can a rhombus have a 90° angle?

Yes, if a rhombus has one 90° angle, then all angles must be 90° (making it a square). This is because opposite angles are equal and adjacent angles are supplementary.

What is the relationship between the diagonals?

In a rhombus, the diagonals are perpendicular bisectors of each other. Also, d₁² + d₂² = 4a² (where a is the side length).

Important Notes

  • All sides of a rhombus must be equal in length
  • The diagonals always intersect at right angles (90°)
  • Interior angles must be between 0° and 180° (exclusive)
  • The sum of all interior angles is always 360°
  • If all angles are 90°, the rhombus becomes a square

Note: This calculator provides mathematical results for geometric shapes. For engineering or construction projects, always consult with qualified professionals and verify measurements.