##  [Sectional Curvature](/sectional-curvature) 

  ##  [Sectional Curvature](https://puremath.quantumdictionary.io/sectional-curvature-0) 

  

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**Pure Mathematics Dictionary**

 







 

 

 

 



 

 

 

 

Definition

For a Riemannian manifold, the sectional curvature K(σ) of a two-dimensional tangent plane σ is the number obtained by evaluating the Riemann curvature tensor on an orthonormal basis of σ and normalizing; it measures the Gaussian curvature of the surface obtained by geodesics tangent to σ.