Complex sentence: The indoor football pitch is covered by a curved steel frame with a PVC roof, the shape of which has been likened to the trajectory of "the goal which defied physics" which was scored by Brazilian football player Roberto Carlos against France in 1997.
Split into simpler sentences: The indoor football pitch is covered by a curved steel frame with a PVC roof. The shape of which has been likened to the trajectory of "the goal which defied physics", scored by Brazilian football player Roberto Carlos against France in 1997.