A door measures 1m wide and 3m tall.how much the lumber is needed to make the door?

1m * 3m = 3m^2

But lumber is usually measured in board feet, so ...

To calculate the amount of lumber needed to make the door, you first need to find the perimeter of the door, as lumber is typically measured in linear feet.

Perimeter of a rectangle = 2 * (width + height)

Given:
Width of the door = 1m
Height of the door = 3m

Substituting these values into the formula:

Perimeter = 2 * (1m + 3m)
= 2 * 4m
= 8m

Therefore, you would need a total of 8 meters of lumber to make the door.

To calculate the amount of lumber needed to make the door, we need to calculate the perimeter of the door frame.

1. Calculate the length of the perimeter: Perimeter = 2 x (Width + Height)
In this case, the width is 1m and the height is 3m.
Perimeter = 2 x (1m + 3m) = 2 x 4m = 8m

2. Determine the total length of lumber needed:
Since the door frame consists of four sides, we multiply the perimeter by 4.
Total length of lumber = Perimeter x 4
Total length of lumber = 8m x 4 = 32m

Therefore, you would need 32 meters of lumber to make the door.