Worked on problems related to the early ideas of calculus today.
The ideas today were closer to integration, finding an area using a summation of infinitely small rectangles using limits.
That meant finding the area of one rectangle and adding up all of them. So a base multiplied by a width.
The actual shape was a triangle and rectangle, but the technique becomes more useful for shapes which are not easy to calculate.
There were quite a few steps, so a single mistake could throw everything off.