How to lay out pictures in the form of triangles?

Question

css

That's what you need
on the hover triangle is filled with background

Answer 1

It is not necessary to duplicate the paths - by default fill: url (#img), by hover fill: #FFA234 - what color do you have there.
Pluses can also be implemented, wrapped with a class or an id, by default opacity: 0, hover for the previous elements - opacity: 1
Example:
https://codepen.io/lagudal/pen/VqaowJ
naturally draw your shapes and pictures.