f h 31 − 2 b f 2 R h h φ R L Derivation of “L” b 2 h L 0 4 ! φ 4 + Prof. Ramesh Singh, Notes by Dr. ) 2 ! Singh/ Dr. Colton φ φ 2 cos 1− 1− = 2 φ circular segment ( ⋅ ⋅ cosφ R 2R + + Taylor’s expansion L f = f h h ⋅φ = = h h R