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Geometry may be one of the oldest branches of mathematics, but it’s much more than a theoretical subject. It’s part of our everyday lives, says Professor Jennifer Taback, and key to understanding many ...

Do you recall your high school geometry? Given isosceles triangle ABC, where side AB is equal to side BC, then angle A is also equal to angle C. That’s not something your math teacher invented—it’s a ...

Compare four sets of pattern blocks. Use pattern blocks to make different shapes. Warm up with a Mystery Math Mistake to tell whether Dotson's 10-frames represent a number less than his focus number.

In the third century BCE, Apollonius of Perga asked how many circles one could draw that would touch three given circles at exactly one point each. It would take 1,800 years to prove the answer: eight ...