Diagonal of a Square Calculator

Calculate square diagonal length using side, area, or perimeter with step-by-step solutions

Calculate Square Diagonal

Length of one side of the square

Square Calculation Results

Enter a valid measurement to calculate the square diagonal
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Example Calculation

Square Tile Example

Problem: Square ceramic tile

Side Length: 30 cm

Find: Diagonal length for cutting purposes

Application: Construction and tiling

Calculation Steps

Given: Side = 30 cm

Formula: d = a × √2

d = 30 × √2

d = 30 × 1.4142

d = 42.426 cm

Square Properties

1

Equal Sides

All four sides are equal in length

2

Right Angles

All four corners are 90°

3

Equal Diagonals

Both diagonals are equal and perpendicular

4

Symmetry

4 lines of symmetry, rotational symmetry

Formula Reference

Diagonal from Side

d = a × √2

Side from Diagonal

a = d / √2

From Area

d = √(2A)

From Perimeter

d = P√2/4

Key Constant

√2 ≈ 1.4142

Understanding Square Diagonals

What is a Square Diagonal?

A square diagonal is a line segment that connects two opposite corners (vertices) of a square. Every square has two diagonals that are equal in length, perpendicular to each other, and bisect each other at the center of the square.

Why Calculate the Diagonal?

  • Cutting materials diagonally
  • Finding distances across square areas
  • Designing square patterns and layouts
  • Solving geometry and trigonometry problems

Mathematical Foundation

d = a × √2

(Special case of Pythagorean Theorem)

The diagonal formula comes from the Pythagorean theorem. A square diagonal creates two 45-45-90 right triangles, where the diagonal is the hypotenuse and the sides are the legs.

Key Relationships

Diagonal to side ratio: √2 : 1 ≈ 1.414 : 1

Area from diagonal: A = d²/2

Circumradius: R = d/2

Inradius: r = a/2 = d/(2√2)

Real-World Applications

  • • Square tile cutting and installation
  • • Picture frame diagonal measurements
  • • Construction and carpentry
  • • Fabric cutting for quilts
  • • Garden and landscape design
  • • Engineering and technical drawings

Special Properties

  • • Diagonals bisect each other at 90°
  • • Each diagonal divides square into 2 triangles
  • • Diagonal creates 45° angles with sides
  • • Square inscribed in circle: d = diameter
  • • Square circumscribed around circle: a = diameter

Related Concepts

  • • 45-45-90 right triangles
  • • Pythagorean theorem
  • • Regular polygon properties
  • • Circle inscribed/circumscribed
  • • Coordinate geometry
  • • Geometric transformations