As shown in the figure, there is rectangular paper ABCD, ab = 6, BC = 8, fold the paper along EF, make point B and point d coincide, and calculate the length of crease EF

As shown in the figure, there is rectangular paper ABCD, ab = 6, BC = 8, fold the paper along EF, make point B and point d coincide, and calculate the length of crease EF

7.5 see figure