Triangle unit assembly block and method using same of building landslide preventing draining retaining wall

Method of building a landslide preventing draining retaining wall using a triangle unit assembly block comprising first and second fastening protrusions disposed to correspond to side surfaces mutually facing each other, and first and second fastening grooves disposed to be misaligned on side surfaces mutually facing each other, wherein the method comprises:

• forming a triangle unit assembly by inserting a first fastening protrusion of a first assembly block into a first fastening groove of a second assembly block, inserting a second fastening protrusion of a second assembly block into a first fastening groove of a third assembly block, and inserting a first protrusion of the third assembly block into a second fastening groove of the first assembly block;
• forming a horizontal assembly by connecting at least two triangle unit assemblies in a horizontal direction;
• and
• forming a structure while stacking adjacent triangle unit assemblies to be misaligned with each other, by stacking at least two horizontal assemblies in a vertical direction.