Surface AreaSurface AreaNets & Rectangular PrismsNets & Rectangular Prisms
Rectangular Prisms
Made of 6 sides
Top & Bottom
Front & Back
Left & Right
Nothing but Net!
A net is the pattern to make a box.
Notice this net will fold up to make the box.
This one too!The net will fold up to create the
box.
Surface Area of a NetFind the area of each rectangle.
8
8
32
3216 16
Add them up! 32321616 88
112+
What about boxes?
Find the area of each side (rectangle)
add them together
Use the Formula
2(l • W) + 2(W • h) + 2(l • h)
or SMILE!!
Length x Width x Height
To find the surface area
Smiley Face Method
Multiply l x w
Multiply w x h
Multiply l x h
Length x Width x Height
This gives you the area ofthe Topthe Sidethe Front
ADD ‘EM UP!!!
You’re Not Done Yet!Since a box has six sides and you’ve only found three sides, you have to double your answer.
It makes no difference
The surface area of a net is the SAME as the surface area of the
box.
Check it out!
3 x 2 = 62 x 6 = 123 x 6 = 18
Adds to36 cm2
Double it!72 cm2
12 1218 18
6
6
Add ‘em up!
72 cm2
They are the SAME!!!