from sectionproperties.pre.library import channel_section

geom = channel_section(d=200, b=75, t_f=12, t_w=6, r=12, n_r=8)
top_geoms, bot_geoms = geom.split_section(
    point_i=(0, 100),
    point_j=(1, 100),
)
(top_geoms[0] + bot_geoms[0]).plot_geometry()