Answer:
It will cost a total of $27.00.
Explanation:
Manny's bedroom door is 9 feet tall and 3 feet wide.
The new door costs $1.00 per square foot.
And we want to find the total cost of the new door.
Since the door is a rectangle 9 feet tall and 3 feet wide, its total area is:
![\displaystyle 9\cdot 3 = 27\text{ ft}^2](https://img.qammunity.org/2022/formulas/mathematics/high-school/3bt4adkz55laxd330mmyr7moowop5msxbx.png)
And since it costs $1.00 per square foot, we can simply multiply it to the total area. Hence:
![\displaystyle 27\text{ ft}^2\cdot \frac{\$ 1}{\text{ ft}^2}=\$27.00](https://img.qammunity.org/2022/formulas/mathematics/high-school/9gcneeqp97nv5o5jp4bpyiazvuho3wwpxc.png)
It will cost a total of $27.00.