first use the formula it is 1/3 × base area × height =volume of pyramid
so we just need to replace some of the information given in the statement to our formula
so it's going to be,i'll let the height as unknown X
128=1/3 × (8 × 8) × X
so it's going to be
128=64/3X
so X is 128 ÷ 64/3=6cm
