Fix gap between path and shapes in Illustrator

I'm working on a cloud image and have created triangles using a template. After the cut and coloring, there are gaps between the triangles. It' about 1 px thick, more prominent when exported to Photoshop:

Is there a quick fix for this?

Edit:

After adding a blue background and saving as a jpeg, the lines become even more visible. Note that I mean the tiny dark blue lines in the background, not the overlay/connection lines. Just curious as to whether there is a way to "expand" these paths.

Answer

There's a Path Offset feature in Illustrator that makes the path go out or in from the shape by an equal amount.

Traditionally this has been used to make fonts heavier or thinner. But will work perfectly for this, too.

Here's a video showing it being used for fonts, but I'm sure you'll immediately see how you can use this technique to solve your problem:

https://www.youtube.com/watch?v=A1-IFcvW1RI

It looks like you'll need a very small number, something like 0.5 might be enough.

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Assuming your goal is to get the Polygons to all be joined perfectly, at their edges, like this:

In which case these 'triangles' are known as Polygons. Traditionally they're done in 3D programs. Which are now, apparently, beyond the scope of this forum. Which is interesting, because you've just highlighted the crossover between 2D and 3D, perfectly.