Answer:
12
Step-by-step explanation:
We know that AD=BC and that AB=CD. We also know the perimeter of the rectangle ABCD to be 54 units.
From this, we can add up the sides which will be equal to 54 units.
AD+BC+AB+CD=54
2x+2x+3x-3+3x-3=54
10x=60
x=6
Since we are trying to find the length of side BC we substitute this value back into 2x.
BC=2x =2*6=12
Therefore, the length of BC is 12 units.
