This is a seated twist pose that stimulates the core and oblique muscles and helps one get a small waist.
The side plank pose works your core and oblique muscles, which helps you get a snatched waist. This also strengthens your core muscles and arms.
This is also known as the boat pose, and while performing this one, one uses their core while helping to shred their waist.
The triangle pose stretches the abdominal muscles and works the core, which helps to get a defined waistline.
Bridge pose requires one to make the movement from their waist, which helps to tone the waistline.
This is basically a plank position. When you perform this asana, your core is under a lot of pressure, which helps make your waist tiny.