This document demonstrates how to calculate the total surface area of a rectangular prism with dimensions of 11cm by 8cm by 5cm. It works through calculating the area of each face (front, back, sides, top, bottom) and sums them to get the total surface area. The front and back areas are each 11cm x 8cm. The side areas are 2 x (8cm x 5cm). The top and bottom areas are each 11cm x 5cm. Adding all the face areas together using a calculator gives the total surface area of 366cm^2.

1. Finding: Surface Area of
Rectangular Prism
- Mr Kim

2. 11cm
8cm
5cm

3. Rectangular Prism
has 6 faces
11cm
8cm
5cm

4. Rectangular Prism
has 6 faces
1

5. Rectangular Prism
has 6 faces
2

6. Rectangular Prism
has 6 faces
3

7. Rectangular Prism
has 6 faces
4

8. Rectangular Prism
has 6 faces
5

9. Rectangular Prism
has 6 faces
6

10. We must calculate the
Total Area of all 6 Faces

11. 11cm
8cm
5cm

12. Front Area is
11cm
8cm
5cm

13. Front Area is
11cm
8cm
5cm
11 x

14. Front Area is
11cm
8cm
5cm
11 x 8

15. 11cm
8cm
5cm
11 x 8
Now, the Back Area is
the same as the Front
so…

16. 11cm
8cm
5cm
11 x 8 x 2
Now, the Back Area is
the same as the Front so
times by 2

17. 11cm
8cm
5cm
11 x 8 x 2
Now we are going to find
the Side Area

18. 11cm
8cm
5cm
11 x 8 x 2
Now we are going to find
the Side Area

19. 11cm
8cm
5cm
11 x 8 x 2 +
Make sure to add that on

20. 11cm
8cm
5cm
11 x 8 x 2 +
So the Side Area is

21. 11cm
8cm
5cm
11 x 8 x 2 + 8 x
So the Side Area is

22. 11cm
8cm
5cm
11 x 8 x 2 + 8 x 5
So the Side Area is

23. 11cm
8cm
5cm
11 x 8 x 2 + 8 x 5
But the other Side is the
same as well so…

24. 11cm
8cm
5cm
11 x 8 x 2 + 8 x 5 x 2
But the other Side is the
same as well so times by 2

25. 11cm
8cm
11 x 8 x 2 + 8 x 5 x 2
5cm
Now we are going to find
the Top Area

26. 11cm
8cm
11 x 8 x 2 + 8 x 5 x 2
5cm
Now we are going to find
the Top Area

27. 11cm
8cm 11 x 8 x 2 + 8 x 5 x 2
+5cm
Make sure to add that on as
well

28. 11cm
8cm 11 x 8 x 2 + 8 x 5 x 2
+5cm
So the Top Area is

29. 11cm
8cm 11 x 8 x 2 + 8 x 5 x 2
+5cm
If it’s 11cm there

30. 11cm
8cm 11 x 8 x 2 + 8 x 5 x 2
+5cm
It’s 11cm there as well
11cm

31. 11cm
8cm 11 x 8 x 2 + 8 x 5 x 2
+ 11 x5cm
It’s 11cm there as well
11cm

32. 11cm
8cm 11 x 8 x 2 + 8 x 5 x 2
+ 11 x5cm
Times by…
11cm

33. 11cm
8cm 11 x 8 x 2 + 8 x 5 x 2
+ 11 x5cm
Times by…
11cm

34. 11cm
8cm 11 x 8 x 2 + 8 x 5 x 2
+ 11 x5cm
If it’s 5 cm down there
11cm

35. 11cm
8cm 11 x 8 x 2 + 8 x 5 x 2
+ 11 x5cm
It’s 5 cm here as well
11cm 5cm

36. 11cm
8cm 11 x 8 x 2 + 8 x 5 x 2
+ 11 x 55cm
It’s 5 cm here as well
11cm 5cm

37. 11cm
8cm 11 x 8 x 2 + 8 x 5 x 2
+ 11 x 55cm
11cm 5cm
But the Bottom Area is the
same as the Top so…

38. 11cm
8cm 11 x 8 x 2 + 8 x 5 x 2
+ 11 x 5 x 25cm
But the Bottom Area is the
same as the Top so times by 2
11cm 5cm

39. 11cm
8cm 11 x 8 x 2 + 8 x 5 x 2
+ 11 x 5 x 25cm
Putting this altogether in the
calculator gives…
11cm 5cm

40. 11cm
8cm
11 x 8 x 2 + 8 x 5 x 2
+ 11 x 5 x 2 = 366cm²5cm
Putting this altogether in the
calculator gives…
Our Final Answer!
11cm 5cm