Contracting versus elongating interface angle measurements and length change data distributions. (A) Histogram of angles for contracting and elongating interfaces during germband extension. (n = 449 contracting interfaces, 387 elongating interfaces, k = 3 embryos); (B) Distribution of measured interface contraction/elongation rates for different interface orientation angle bins, constrained to the time window t = 4–6 min after initiation of germband extension. (n = 2,940 interfaces, k = 3 embryos); (B′) Same as B but constrained to the time window t = 19–21 min after initiation of germband extension. (C) Distribution of measured interface contraction or elongation rates for different interface orientation angle bins, constrained to the cell area oscillation phase 180° (n = 2,940 interfaces, k = 3 embryos). (C′) Same as C but constrained to the cell cycle phase 360°.