1. Surface Area of Rectangle Prisms
EQ:
How do you find the surface area of rectangle prisms?
Surface Area of Rectangle Prisms

2. What are the dimensions of this rectangle?
4 cm 7 cm 10
Do you see the RED face?
What are the dimensions of this rectangle?
4 cm
10 cm

3. Do you see another face that is just like the RED face?
4 cm 7 cm 10
Do you see another face that is just like the RED face?
Where is it located?
Keep an eye on the next screen!

4. Yes, it’s on the back.
10cm
4 cm

5. 40cm2
Now there are 2 rectangles
that each have an area of 40 sq. cm

6. What are the dimensions of this rectangle?
4 cm 7 cm 10
Do you see the BLUE face?
What are the dimensions of this rectangle?
4 cm
7 cm

7. Do you see another face that is just like the BLUE face?
4 cm 7 cm 10
Do you see another face that is just like the BLUE face?
Where is it located?

8. Yes, it’s on the left side.
7 cm
4 cm
4 cm
7 cm

9. 28cm2
Now there are 2 rectangles
that each have an area of 28 sq. cm.

10. Do you see the GREEN face?
4cm 7 cm
10cm
Do you see the GREEN face?
What are the dimensions of this rectangle?
7 cm
10 cm

11. Do you see another face that is just like the GREEN face?
4 cm 7 cm 10
Do you see another face that is just like the GREEN face?
Where is it located?

12. Yes, it’s on the bottom.
10cm
7 cm
10cm
7 cm

13. 70cm2
Now there are 2 rectangles
that each have an area of 70 sq. cm.

14. Now we just need to add all the areas of the sides together.+
70cm2
28cm2
40cm2

15. The total Surface Area for this rectangular prism is=
276cm2

16. Since we know that a rectangle prisms can “unfold” into 6 rectangles, we can use a net to help us find the surface area.
Top
Side
Front

17. Find the AREA for each rectangle. (Length X Width)
Height 8
Length 12
Width 4 12
12 x 4 4
48 sq units
12 x 8 8
96 sq units 12
12 x 4 4
48 sq units 8
12 x 8 8 32
96 sq units 32
8 x 4
8 x 4 4 12 4

18. Transfer the dimensions from the 3-D figure to the flattened figure
Dimensions: Length – 12 (the longest side) Height – 8 (top to bottom) Width – 4 (front to back) 8 12 4
Height 8
Length 12
Width 4