What is the area of a ring (an annulus), the region between two concentric circles? The line segment is tangent to the inner circle and has a length of 8. The answer is surprising and there are several ways to solve the problem. In the video I present four solution methods and also mention a fifth method that is an introduction to visual calculus.

Desmos interactive
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My blog post for this video (sources and links for further exploration)
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"The Irrationality Illusion: How To Make Smart Decisions And Overcome Bias" is a handbook that explains the many ways we are biased about decision-making and offers techniques to make smart decisions. (rated 5/5 stars on 2 reviews) https://www.amazon.com/gp/product/1523231467/

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