**Trapezoidal sums (video) | Khan Academy**
https://www.khanacademy.org/math/ap-calculus-ab/ab-integration-new/ab-6-2/v/trapezoidal-approximation-of-area-under-curve

The area under a curve is commonly approximated using rectangles (e.g. left, right, and midpoint Riemann sums), but it can also be approximated by trapezoids. Trapezoidal sums actually …

**DA:** 45 **PA:** 37 **MOZ Rank:** 97