Answer:
10 2/5 inches
Step-by-step explanation:
Since P=2L+2W, we can flip it to find the length. For example, we could minus 2L from both sides to get P-2L=2W.
We already know that W is 4.5, and P is 29.4.
Plugging that in, we get 29.4-2L=9. Again we can flip the perimeter, and -29.4 on both sides. This would make -2L=-20.4.
For our last flip, we divide the -2 from both sides to finally get L=10.2 (or 10 1/5 if you want) inches.
