total surface area of rectangular prism
TRANSCRIPT
Each side of a rectangular prism is called a face.
A rectangular prism has six faces.
In a rectangular prism there are 3 pairs of opposite and equal sides. The first pair is the red face
7 cm (l)
4 cm (b)
10 cm (h)
10 cm (h
7 cm (l)
We can see another face - just like the red face. That is on the back.
7 cm(l)
10 cm(h)
7 cm(l)
10 cm(h)
Now there are 2 rectangles that each have an area of 70cm² ie
lh+lh=2lh
l x h= 7 x 10= 70cm²
70 cm
2
70 cm
2
The second pair is the blue face
10 cm (h)
4 cm (b)
7 cm (l)
4 cm (b)
10 cm (h)
We can see another face - just like the blue face. That is on the left side.
10 cm (h)
4 cm (b)
4 cm (b)
10 cm (h)
Now there are 2 rectangles that each have an area of 40cm² ie
bh+bh=2bh
40cm²
40cm²
b x h= 4 x 10= 40cm²
The third pair is the green face
10 cm (h)
4 cm (b)
7 cm (l)
7 cm (l)
4 cm (b)
We can see another face - just like the green face. That is on the bottom.
4 cm (b) 4 cm (b)
7 cm (l) 7 cm (l)
Now there are 2 rectangles that each have an area of 28cm² ie
lb+lb=2lb
28cm²
28cm²
l x b= 7 x 4= 28cm²
Now we just need to add all the areas of the sides together.
+ +
+ + 28cm
2
40cm
2
70cm
2
70cm
2
40cm
2
28cm
2
The total surface area for this rectangular prism is