Six siblings arrive at a photographer’s studio to have pictures taken. in how many ways can the photographer arrange the six siblings for the photo?

There are n! ways of arranging n elements. This is because you have n possible choices for the first position, the remaining n-1 choices for the second position, and so on, until you're forced to pick the only remaining option.

So, there are

ways of arranging 6 elements in a certain order.

a net is a diagram that shows a “flattened” view of a solid. in a net, each face and base is shown with all of its dimensions. a net can also serve as a pattern to build a three-dimensional solid.

a pyramid is a three-dimensional object with a base that is a polygon and triangular faces that meet at one vertex.

" the net of a triangular pyramid consists of four triangles. the base here we are given of the pyramid is a equilateral   triangle, and the lateral faces are also triangles "