Let's break down the problem step by step.

Step 1: Find the area of each wall.

The room is a rectangular prism with dimensions:

• Length: 15 ft
• Width: 12 ft
• Height: 8 ft

There are four walls in total, two pairs of opposite walls:

1. Two walls with dimensions 15 ft by 8 ft
2. Two walls with dimensions 12 ft by 8 ft

Area of the long walls (15 ft by 8 ft):

$\text{Area} = 15 \times 8 = 120 \text{ square feet}$ There are two such walls, so: $2 \times 120 = 240 \text{ square feet}$

Area of the short walls (12 ft by 8 ft):

$\text{Area} = 12 \times 8 = 96 \text{ square feet}$ There are two such walls, so: $2 \times 96 = 192 \text{ square feet}$

Step 2: Find the area of the ceiling.

The ceiling is a rectangle with dimensions 15 ft by 12 ft: $\text{Area} = 15 \times 12 = 180 \text{ square feet}$

Step 3: Subtract the areas of the door and window.

• The door has dimensions 3 ft by 7 ft: $\text{Area of door} = 3 \times 7 = 21 \text{ square feet}$
• The window has dimensions 6 ft by 4 ft: $\text{Area of window} = 6 \times 4 = 24 \text{ square feet}$

Step 4: Calculate the total area to be painted.

We add the areas of the four walls and the ceiling, then subtract the areas of the door and window: $\text{Total area} = (240 + 192 + 180) - (21 + 24)$ $\text{Total area} = 612 - 45 = 567 \text{ square feet}$

Step 5: Calculate the number of gallons of paint needed.

Each gallon of paint covers 300 square feet. To find how many gallons are needed: $\text{Gallons of paint} = \frac{567}{300} \approx 1.89 \text{ gallons}$ Rounding up, Annalea will need 2 gallons of paint.

Would you like further details or have any questions?

5 Related Questions:

1. What if the ceiling were a different height, say 10 feet? How would this affect the total area to be painted?
2. How would adding a second window of the same size affect the number of gallons required?
3. If the paint only covered 250 square feet per gallon, how many gallons would be needed?
4. What if the room were 20 ft by 15 ft, but the same height? How much more paint would be required?
5. How would the calculations change if there were no door or window in the room?

Tip:

When calculating areas for walls and surfaces, always remember to subtract spaces for windows and doors to avoid overestimating paint or material requirements!