Answer:
12m
Step-by-step explanation:
The two trapezoids are similar!
so they will have equal ratio at same shape/part!
now the ratio of upper side of larger to smaller is 6/3=2
clearly it suggest that all the other side becomes the half of it corresponsing similar side,
like, for right side of larger trapezoid corresponds to b of smaller,
larger have length 4cm,so it corresponding b will have length 4cm/2, i.e, 2cm=b
similarly, c = 4cm/2 =2cm
and a= 10cm/2=5cm
now, perimeter of the smaller garden will be sum of it's all side
i.e, a+b+c+3m
i.e,5m+2m+2m+3m
i.e,12m
✌️:)
