4. A wallpapaer border on top of the baseboard on a flight of stairs is in the shape of a parallelogram. The bottom of the border is $150 \mathrm{~cm}$ and the height is $12 \mathrm{~cm}$. What is the area of the border?
Answer
Solving this, we find that the area of the border is \(\boxed{1800}\) square cm.
Step 1 ：The problem is asking for the area of a wallpaper border on top of the baseboard on a flight of stairs, which is in the shape of a parallelogram.
Step 2 ：The formula for the area of a parallelogram is given by \(\text{Area} = \text{base} \times \text{height}\).
Step 3 ：In this case, the base of the parallelogram is given as 150 cm and the height is given as 12 cm.
Step 4 ：Substituting these values into the formula, we get \(\text{Area} = 150 \times 12\).
Step 5 ：Solving this, we find that the area of the border is \(\boxed{1800}\) square cm.
