Yes, it is! If you check the Tip and notes in the web version you will see how the articles agree with the nouns in grammatical gender, number and case. :)
I know this question is out of context, but is there any way one could memorize if the noun is feminine or neutral or masculine? Are there any rules one should know? Because i am having trouble memorizing genders for each noun. Thank you
There are some gender patterns but a lot of endings are shared. You can find a good guide here: http://www.foundalis.com/lan/grknouns.htm. You have to remember though that what is listed there is the nominative case only. This means that when for example the final -ς is dropped in other singular cases for masculine nouns, they will look like another gender.
I think that unfortunately you will have to memorise each noun with its gender. However, the more words you learn the more obvious the patterns will become and you'll get a better feel for it. And don't worry about making yourself understood, mistakes and all. The efforts of non-native speakers are always appreciated. :)