As shown in the figure, it is known that the line segment ad = 10cm, the line segment AC = BD = 6cm. E and F are the midpoint of the line segments AB and CD respectively, and the length of EF is calculated
∵ ad = 10, AC = BD = 6, ∵ AB = ad-bd = 10-6 = 4, ∵ e is the midpoint of the line AB, ∵ EB = 12ab = 12 × 4 = 2, ∵ BC = ac-ab = 6-4 = 2, CD = bd-bc = 6-2 = 4, ∵ f is the midpoint of the line CD, ∵ CF = 12CD = 12 × 4 = 2, ∵ EF = EB + BC + CF = 2 + 2 + 2 = 6cm