What is surface area?
surface area is all of the showing sides’s area put together to make the surface area of that object.
to find the surface area of a 3 dimensional square that has sides of 4 cm by 4 cm and a height of 4 cm you will need to calculate the surface area of one of the sizes and then multiply it by 6. (6 because there is 6 sides of a 3 dimensional square.)
4x4x6=SA
the surface area of this square is 96 cm squared.
How to find the surface area for rectangles
to find the surface area of a rectangle you need to get the width, the length and the height. Once you have that you need to follow this formula.
2WL + 2LH + 2WH = SA
If you know the surface area of two object before they were put together, then you know the surface area of them together.
ex: if you have a rectangle with a width of 3 cm, a height of 10 cm and a length of 5 cm then you’ll have a surface area of 190 cm squared. and if you have another rectangle for simplification of this explanation I’m going to say its the exact same dimensions of the first rectangle if you put end to end you’ll get a surface area of both the objects combined minus the end area that’s touching the other object times 2.
so this newly formed double rectangle would have a surface area of 380-15×2
aka: 350 cm squared
(here’s the formula)
1SA+2SA-2X=3SA
(x is the surface area that touches the other object.) (3SA is the new combined shape.)