Test your knowledge of taxicab geometry, triangular numbers, the golden ratio and more. Credit... Supported by By Steven Strogatz “Math, Revealed,” our four-part series exploring the ...

Each day brings a greater triangular number of gifts. But how can we compute the total number without actually adding them up? We need to sum the first 12 triangular numbers.

Not deducible Harry and Tom have each found a 4-digit perfect square, a 3-digit perfect cube and a 3-digit triangular number that use 10 different digits, but with no leading zero. A triangular ...