Lila is wallpapering one wall of her bedroom, as shown in the diagram. She will cover the whole wall except for the doorway. How many square feet of wall does Lila  need to cover?

First, find the area of the wall.

\(\begin{aligned}
A&=b\times h\\
\end{aligned}\)

Next, find the area of the door.

\(\begin{aligned}
A&=b\times h\\
\end{aligned}\)

Last, subtract the area of the door from the area of the wall.

_____ – _____ = _____ square feet

So, Lila needs to cover _____ of wall.

What if there was a square window on the wall with a side length of 2 feet? How much wall would Lila need to cover then? Explain.

Ed is building a model of a house with a flat roof, as shown in the diagram. There is a chimney through the roof. Ed will cover the roof with square tiles. If the area  of each tile is 1 square inch, how many tiles will he need? Explain.