Answer:
SV
Explanation:
From the given figure STUV is a quadrilateral, SV and TU are the diagonals of the given quadrilateral.
The diagonals of the given quadrilateral divides it into four triangles.
Consider two big triangles that are SUV and VTS, in both these triangles, SV is the only side which is common in both the triangles.
Thus, SV is the common side of the triangles SUV and VTS.