Câu 1: trang 168 - toán tiếng anh lớp 5A rectangular classroom has a length of 6m, a width of 4,5m...

In conclusion, they need to paint a total area of 90.5 square meters to complete the task.

So, the total area that needs to be painted is 90.5m2.

Therefore, the total area that needs to be painted is the sum of the ceiling area and the total area of the walls: 27m2 (ceiling) + 72m2 (walls) - 8.5m2 (area of doors) = 90.5m2.

The area of each wall is equal to the height of the room multiplied by the width of the room. Since there are four walls, the total area of the walls is: 4m x 4.5m x 4 = 72m2.

The area of the ceiling can be found by multiplying the length and width of the room: 6m x 4.5m = 27m2.