HAI
The diagonals of the rhombus are in the middle of the rhombus or inside of it so if you are trying to find the sides of the rhombus all you have to do is know what the diagonals are.
So if the diagonals are 8 and 6 cm, then the lengths of the sides are 4 because its like doing a radius. You can divide 8 into 2 and get 4.
Answer: So the lengths of the sides are 4 cm.
Hope this helps!! :D