Five prehistoric clay puppets with revolving heads have been discovered in El Salvador, a country in North America.

The pyramid builders must have measured incredibly ... To make it a square, each of these angles needs to be a right angle. You can check that they are by measuring across the diagonals - here ...

It may be necessary to use Pythagoras' theorem and trigonometry to solve a problem. The shape ABCDEFGH is a cuboid. Length AB is 6 cm, length BG is 3 cm and length FG ...

Each side of the Great Pyramid rises at an angle of 51.5 degrees to the top. Not only that, each of the sides are aligned almost exactly with true north, south, east, and west. For a pyramid to ...

The bent pyramid was then readjusted in order for the angle to be less steep and for better stabilisation. Today, the pyramid’s appearance remains unusual, with the first 49 metres from the base ...