Originally, each country had its own, and rather poorly reproducible, unit of luminous intensity; it was necessary to wait until 1909 to see a beginning of unification on the international level, when ... Continue reading
Cones are used every day for a variety of purposes. Perhaps the most useful application of the cone shape is as a funnel. For finding the volume, a cone is best viewed as a stack of circles, each one ... Continue reading
A prime number is a number that is divisible only by one and by itself. Factors are numbers that can be divided into a number with no remainder. The factors of 18 are the numbers 1, 2, 3, 6, 9, and ... Continue reading
The cone is another three-dimensional shape based on the circle. You could think of it as the cross between a circle and a right triangle. Its properties will have features of both shapes, and this ... Continue reading
