Let the height of the original pyramid be represented by h. Then the cut off top has a height of (h -2). The scale factor for the area is the square of the scale factor for height, so we have ...
(height ratio)^2 = 1/2
((h -2)/h)^2 = 1/2
(h -2)√2 = h . . . . . . square root; multiply by h√2
h(√2 -1) = 2√2 . . . . add 2√2 -h
h = (2√2)/(√2 -1) ≈ 6.8284 . . . units
The altitude of the original pyramid is about 6.83 units.
