Answer:
x=20cm
y=6cm
Explanation:
We are told ΔABC and ΔPQr are similar. This means their corresponding sides are in ratios to one another.
That means the ratio of AB to PQ, is equal to the ratio of AC to PR, is equal to the ratio of BC to QR. Written mathematically, this is:

Find x/PR
Since we know the values of AB, PQ, and AC, we can use
to find PR (x):


1.5=

1.5x=30
x=20
Find y/QR
Since we know the values of AB, PQ, and BC, we can use
to find QR (y):

1.5=

1.5y=0
y=6