Tangents to the circle with center (0, 2) and radius 1.8 passing through (2, 3):

We can draw the circle with (possiamo tracciare il cerchio con) circle_3.

Or: we can draw the circle with (ovvero possiamo tracciare il cerchio con) circle_3b  (see the code;  se also here).

The equations of T1 and T2:
80.17380689297816° = 80.17380689297816/180·π = 1.39929690414059
152.95629546117783° = 152.95629546117783/180·π = 2.66959096745081
T1:   x → Q2 + (x − Q1)·tan(dir T1)  =  1.692812060377645 + (x - 1.773593969811178)·tan(1.39929690414059)
T2:   x → R2 + (x − R1)·tan(dir T2)  =  3.603187939622355 + (x - 0.81840603018882)·tan(2.66959096745081)