In anatomy, the point of articulation is where two or more bones make contact.
Tarsal bones are a group of bones comprising the human foot, while the tibia (shinbone) and fibula are bones comprising your lower leg.
The tarsal that articulates (connects) with the tibia and fibula is the talus. This is more clearly seen in the figure below.
(Figure source: https://en.wikipedia.org/wiki/Talus_bone#/media/File:Blausen_0411_FootAnatomy.png)