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The circumference of a circle is the distance around the shape. The ability to round a number to a number of decimal places or to a number of significant figures means that answers can be written to ...

Wheel bolt-circle diameter is the diameter of a circle drawn through the centers of the wheel's mounting-bolt holes. Whether shopping for new wheels or scrounging wrecking yards for good used ones, ...

Some spare time recently got used-up designing a pair of involute gears – which, it transpires, is easy in principle, once certain almost-impossible-to-obtain facts have been gathered. There are ...