What is the surface area of a box with no lid that is 75 cm long, 0.4 m wide, and 200 mm high?
To calculate the surface area of a box with no lid, we need to find the area of each of the 5 sides: the two sides, the bottom, and the front and back.
Given:
Length = 75 cm = 0.75 m
Width = 0.4 m
Height = 200 mm = 0.2 m
1. Front and back side:
Area = length x height = 0.75m x 0.2m = 0.15 m^2
There are two front and back sides, so the total area of the front and back sides is 0.15m^2 x 2 = 0.3m^2
2. Two sides:
Area = width x height = 0.4m x 0.2m = 0.08 m^2
There are two sides, so the total area of the sides is 0.08m^2 x 2 = 0.16m^2
3. Bottom:
Area = length x width = 0.75m x 0.4m = 0.3 m^2
Now, add up the areas of all 5 sides to find the total surface area:
0.3 m^2 (front and back) + 0.16 m^2 (sides) + 0.3 m^2 (bottom) = 0.76 m^2
Therefore, the surface area of the box is 0.76 square meters.