Core Connections in Integrated Spanish II Lesson 11.1.1 11-7. height ≈ 5 cm; SA ≈ 1438.4 cm2 11-8. 24 square units; Since DE is a midsegment, DE=1 2 BC. If the ratio of the lengths of the sides is 0.5, then the ratio of the areas is 0.52 = 0.25.