# Riemann Sum

A Riemann sum is an estimate, using rectangles, of the area under a curve. A definite integral is defined as a limit of Riemann sums.

Riemann sum is a college-level concept that would be first encountered in a Calculus I course. It is an Advanced Placement Calculus AB topic and is listed in the California State Standards for Calculus.

### Prerequisites

Definite Integral: | A definite integral is an integral with upper and lower limits. |