## Elementary Geometry for College Students (6th Edition)

$BC = 12.3$
We can find $BC$: $P = AB+BC+CD+DA = 59.2$ $AB+BC+BC+AB = 59.2$ $(BC+5)+BC+BC+(BC+5) = 59.2$ $4~BC+10 = 59.2$ $4~BC = 49.2$ $BC = \frac{49.2}{4}$ $BC = 12.3$