RHS congruency rule says that
2 right angled triangles are congruent if they have their hypotenuse and one side equal.
Technically it also means that their all sides will become equal.
But the difference from SSS rule is that
SSS rule is applicable in ANY triangle, but RHS rule is applied ONLY in right angled triangles.
The 3 conditions for RHS are Right Angle, Hypotenuse and Side.
Whereas for SSS are Iside, IIside and IIIside.
Use RHS only if one angle is right angle in the triangle, otherwise use SSS.
You can use SSS in all types of triangles but you can use RHS only if the triangle
is right angle traingle.