Given that,
Side of rhombus = 6 cm
Altitude of rhombus = 4 cm
Since rhombus is a parallelogram, therefore area of parallelogram = base × altitude
i.e., Area of parallelogram = 6 × 4 = 24 cm2
Area of parallelogram = Area of rhombus
Area of rhombus = 1/2 × d1 × d2
24 = 1/2 × 8 × d2
24 = 4 × d2
d2 = 24/4 = 6
So, length of other diagonal of rhombus is 6 cm