A Christmas decoration is in the shape of a square based pyramid. All edges in the pyramid have a measurement of 4cm how do you find the height of the pyramid?
Calculate the height of an equilateral triangle with sides all
A triangular face of the pyramid is equilateral, so divides into two right angled triangles with sides
Then looked at from one side, the pyramid looks like a isosceles triangle with base
Alternatively, note that stacking two of these pyramids back to back will result in a regular octohedron, who diagonal measurement is the diagonal of a square with sides of length