China Naming Network - Eight-character Q&A - Osmunda skeleton
Osmunda skeleton
25.12/3.14 = 8cm (bottom diameter)
112/2/8 = 7cm (cylinder height)
25. 12 * 7 = 175.84 cm2 (horizontal area)
8/2 = 4cm (radius)
3.14 * 4 * 4 = 50.24cm2 (bottom area)
50.24 * 2+ 175.84 = 276.32 cm2 (surface area)