This pattern is worked from bottom up in a straight line which gets larger in every row , to shape it into a square after certain chosen rows, it is decreased in one side in every row till only 2 stitches are left and shaped into the V stitch square. The increase of this triangle is similar to the basic triangle which happens at the beginning of every row.

Materials 

Medium worsted yarn (4)

Crochet hook: 5.5 mm / 6mm