Trikonasana

The name comes from the Sanskrit words utthita (उत्थित), "extended", trikoṇa (त्रिकोण) "triangle",[4] and āsana (आसन) "posture" or "seat".

[5] The pose is first described in the 20th century, appearing in the teaching of Tirumalai Krishnamacharya, including his 1934 book Yoga Makaranda, and in the works of his students.

Once the trunk is fully extended to the right, the right arm is dropped so that the right hand reaches the shin (or a block or on the floor)[7] to the front (left side) of the right foot, with the palm down if flexed.

The left arm is extended vertically, and the spine and trunk are gently twisted counterclockwise (i.e., upwards to the left, since they're roughly parallel to the floor), using the extended arms as a lever, while the spine remains parallel to the ground.

The arms are stretched away from one another, and the head may be turned to gaze at the left thumb, slightly intensifying the spinal twist.

The fourth has the legs straight, both feet pointing slightly out, and the body held horizontally with the arms out to the sides.