This Mathologer video talks about applying a similar approach to some 3D calculus problems - although the tangent swept shapes are arcs not triangles. https://w

This Mathologer video talks about applying a similar approach to some 3D calculus problems - although the tangent swept shapes are arcs not triangles. https://www.youtube.com/watch?v=5q_sfXY-va8&t=0s https://www.youtube.com/watch?v=5q_sfXY-va8&t=0s The model of taking the same swept shapes and rearranging them into another shape whose area or volume is easy to calculate is the same approach though.