Total surface area of rectangular prism

4.  Each side of a rectangular prism is called a face.
 A rectangular prism has six faces.

5. 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)

6. 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)

7. 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

8. The second pair is the blue face
10 cm (h)
4 cm (b)
7 cm (l)
4 cm (b)
10 cm (h)

9. 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)

10. 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

11. The third pair is the green face
10 cm
(h)
4 cm
(b)
7 cm
(l)
7 cm (l)
4 cm (b)

12. 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)

13. 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

14. 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

15. The total surface area for this
rectangular prism is