I have a problem in the category you view the articles but the preview images are scaled wrong, I do not understand why the width and the height is correct however is not correct and as you can see I am going over the alignment of the page ...

how should I do to make sure that the preview images are all the same size?

here is the link of the page to see the problem of incorrect resizing of photos: www.tgtourism.tv/news.html

please help me!

The quick and easy solution is css. So learn it.

Open www.tgtourism.tv/templates/gk_twn2/css/k2.css , go to line 137 and make it look like this (just copy and paste):