Answer: The Length of BC is 4x-10 units.
Step-by-step explanation:
Since we have given that
Length of AC = 8x-20
And B is the mid point of AC.
And we know that Length of BC is the half of the length of AC.
So, Length of BC would be
[tex]\dfrac{8x-20}{2}\\\\=\dfrac{8x}{2}-\dfrac{20}{2}\\\\=4x-10[/tex]
Hence, the Length of BC is 4x-10 units.