Respuesta :

jleaff

Answer:

4 cm

Step-by-step explanation:

Perimeter of a parallelogram is 2b+2h=30 where b is base and h is height.

if AD is 3cm more than twice AB, then it's 3+2x where x is length of AB.

Input this into the perimeter equation: 2(3+2x)+2(x)=30

Simplify to get 6+6x=30

x=24/6=4

Answer is 4 cm.