Question

In rhombus fmkw mk=12 fk= 16 m

Answer 1

If it is area your looking for.

Area = product of diagonal lengths divided by 2

Area = 12* 16 /2

         =192/2  = 96.

IF it is the side length of the rhombus:

apply Pythagoras theorem since the diagonals always meet at 90°.

L =√(12² + 16²)

L= √400 = 20