CREATE TABLE table_2071644_2 (weight__kg_m_ VARCHAR, cross_section_area__cm_2__ VARCHAR)

If the cross-section area is 21.2, what is the weight?
SELECT weight__kg_m_ FROM table_2071644_2 WHERE cross_section_area__cm_2__ = "21.2"
SELECT "weight__kg_m_" FROM "table_2071644_2" WHERE "21.2" = "cross_section_area__cm_2__"