Black holes – Space science – Physics
A starry sky with the Milky Way galaxy (thanks to Bernd Nies) - there are probably black holes in there somewhere! What is a black hole? A black hole is [...]
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08, 2017
29
07, 2017
Area of a sphere – Volume of a sphere
This is a sphere. A sphere is a three-dimensional circle. Or you could say that a sphere is the set of all the points that are at the same distance from the center [...]
29
07, 2017
What is a pyramid? Square pyramids
A pyramid with a square base. A pyramid is a three-dimensional solid form made out of triangles. Some pyramids also use a square. There are two common kinds of pyramids: triangular pyramids that you [...]
29
07, 2017
What is a prism? Rectangular and triangular prisms
This is a triangular prism A prism is the solid shape you get if you move a flat polygon through space. A prism has five planes: a top, a bottom, and [...]
29
07, 2017
What is a cylinder? Simple geometry
This is a cylinder. What can you find around your house that's a cylinder? A cylinder is a circle moved through space to make a solid form. The ends are circles that [...]
29
07, 2017
Volume of a cone – Geometry
How much ice cream fits inside this cone? A cone is the set of all the line segments that start from one circle and go to a point not on the circle. You could think of [...]
7
06, 2017
Math and Numbers in Ancient China
Chinese numbers: number rods Chinese numbers People in China were using written numbers by about 1500 BC, in the Shang Dynasty. This is about two thousand years later than people began [...]
7
06, 2017
What are the Nine Chapters? Math in Ancient China
Nine Chapters: How to figure out the area of an isosceles triangle. A math textbook from Han Dynasty China The earliest Chinese mathematical textbook is called the Nine Chapters. It [...]
