Let the side length of the upper and lower sides of a regular triangular platform be 2cm and 5cm respectively, and the side edge length be 5cm

If we draw a regular triangular pyramid, connect the center of the upper and lower bottom surfaces, CC1, connect AC, BC, then AC = 533-233 = 3, ab = 5, ｜ BC = oo1 = AB2 − ac2 = 22, that is, the height of the pyramid is 22cm

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