Can someone plsss tell me how to work this out??
20 POINTS

53

Step-by-step explanation:

64 is a square, leaving you with 4 digits. 78 is a triangular number, leaving you with the digits 3 and 5. These can be put together to form 53, which is a prime, and therefore the one that she writes down. Hope this helps!

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 "

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.