Basic College Mathematics (9th Edition)

Perimeter of the Parallelogram = $P$ P= 10.0 cm
Perimeter of a Parallelogram: $P$ = $a$ + $b$ + $c$ + $d$ Therefore: $P$ = 2.5 cm + 2.5 cm + 2.5 cm + 2.5 cm P = 10.0 cm