Linked from

The 47 pages that link to Radian, each with the reason it gives.

• CircleRelated: It connects angular measure directly to a circle’s radius and arc.

• AngleRelated: Radians measure angles naturally through the geometry of a circle.

• Angular velocityRelated: Radians make the relation between angular and tangential speed direct.

• Arc lengthRelated: Radians make the circular arc-length relation simply length equals radius times angle.

• SineRelated: Radians make sine’s period and calculus formulas especially direct.

• Euler's formulaRelated: The angle θ is conventionally measured in radians for the identity.

• Trigonometric functionsRelated: Radians make periodic formulas and calculus identities especially direct.

• TrigonometryRelated: Radians connect angle measure directly to circular distance and calculus.

• Unit circleRelated: On a unit circle, an angle in radians equals the length of its intercepted arc.

• PiRelated: A full turn measures 2π radians, linking pi to angular measurement.

• Reduced Planck constantRelated: The factor 2π arises when frequency is expressed per radian rather than per cycle.

• CosineRelated: Radians make cosine’s input align directly with motion around the unit circle.

• WavenumberRelated: Angular wavenumber uses radians to express phase change per unit distance.

• Circular motionRelated: Radians make angular displacement directly comparable to distance traveled along the circle.

• Polar coordinate systemRelated: Radians make polar formulas and calculus especially direct.

• Spherical trigonometryRelated: Radians make arc lengths and angular measurements on a sphere directly comparable.

• Central angleRelated: Radians express central angles directly through arc length and radius.

• Uniform circular motionRelated: Radians make the relation between angular speed, radius, and linear speed direct.

• Small-angle approximationRelated: The approximation works in this unit because the angle then equals the leading term of tangent’s expansion.

• Inverse trigonometric functionsRelated: Inverse trigonometric outputs are conventionally expressed in radians in analysis.

• Right angleRelated: The same quarter-turn measures π/2 radians.

• TangentRelated: Tangent’s period and standard values are commonly expressed in radians.

• Angular displacementRelated: Radians provide the standard unit for expressing angular displacement in equations.

• Euler's identityRelated: Euler's formula uses radians, so π denotes a half-turn rather than a degree measure.

• Polar formRelated: Radians make angle formulas for exponentials and powers especially direct.

• Spherical law of cosinesRelated: Spherical side lengths are often expressed as angles in radians.

• Angular accelerationRelated: Using radians makes angular and tangential acceleration relate directly through the radius.

• Spherical coordinate systemRelated: Radians make the coordinate formulas for spherical geometry especially direct.

• Spherical excessRelated: Area formulas express spherical excess most directly when angles are measured in radians.

• SteradianRelated: Its arc-to-radius definition parallels the steradian’s area-to-radius-squared definition.

• Sine and cosineRelated: Radians make the unit-circle definitions and calculus formulas especially direct.

• Revolutions per minuteRelated: Radians provide the angular measure used to convert rpm into angular velocity.

• Differentiation of trigonometric functionsRelated: The standard derivatives of sine and cosine hold in this simple form when angles are measured in radians.

• Legendre's theorem on spherical trianglesRelated: Spherical excess and curvature formulas are naturally expressed using radians.

• Mollweide's formulaRelated: Writing the triangle angle sum as π clarifies the half-angle expressions.

• StadimeterRelated: The distance relation is simplest when the measured angle is expressed in radians.