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1) What is an equivalent expression for 3 + 6y + 8 + 2y?
a) 8y + 11b) 8y2 + 11c) 9y + 10 d) 19y2
April 7, MondayDay E
April 7, MondayDay E
Absent ? Check Extras!!
› Activator› Expectations› Finding the surface area of
rectangular prisms.› Ticket to Go
Expectations1) Listen and follow directions.2) Raise your hand before speaking or
leaving your seat.3) Keep your hands and your feet to
yourself.4) Respect your classmates and your
teacher.
For Valentine’s Day
would like to pick up this building,…
wrap it,…
and give it to Mrs. Godzilla.
, Godzilla…
5
Godzilla’s Problem
Wrapping paper is expensive! I want to use as little as possible. How could I calculate how much wrapping paper I would need to exactly cover the building without any paper overlapping?
The exact amount of paper needed to cover a rectangular prism (or box) is called the Surface Area.
FrontSide
Top
Review: Finding Surface Area
We can unfold the prism into a net to help us find its surface area.
Front
Top
SideSide
Bottom
Back
4 cm2 cm
3 cm
Front
Back
Side 1
Side 2
Top
Bottom
Take a couple minutes to see how many faces you can find the area of. If you can, also try to find the total surface area.
How do we find the surface area of this rectangular prism?
4 cm2 cm
3 cm
Surface area of the rectangular prism
4 cm2 cm
3 cmFront
Side
Top
Front = 4 cm x 3 cm = 12 cm2
= 4 cm x 3 cm = 12 cm2
= 2 cm x 3 cm = 6 cm2
= 2 cm x 3 cm = 6 cm2
= 4 cm x 2 cm = 8 cm2
= 4 cm x 2 cm = 8 cm2
52 cm2
+
3 34
422
BackSide 2
Bottom
Back
Side 1
Side 2Top
Bottom
Front
Top
SideSide
Bottom
Back
Remember:
Class Work: finding the surface area of rectangular prisms
6.G.4
If you finish early, try to think of a formula to find
the surface area of a rectangular prism.
Problem # 1a
12 x 2 = 24 in2 12 x 2 = 24 in2
3 x 12 = 36 in2
3 x 12 = 36 in2
3 x 2 = 6 in2
3 x 2 = 6 in2
Surface Area = 132 in2
Problem # 1b
8 x 6 = 48 m2 8 x 6 = 48 m2
8 x 22 = 176 m2
8 x 22 = 176 m2
6 x 22 = 132 m2
6 x 22 = 132 m2
Surface Area = 712 m2
Problem # 1c
29 x 16 = 464 ft2 29 x 16 = 464 ft2
29 x 23 = 667 ft2
29 x 23 = 667 ft2
16 x 23 = 368 ft2
16 x 23 = 368 ft2
Surface Area = 2998 ft2
29 ft.
Wrapping paper is expensive! I want to use as little as possible. How much wrapping paper would I need to exactly cover the building without any paper overlapping?
40 ft80 ft
200 ftFront
Side
Top
That’s a lot of paper! Thanks Honey!
Front
Back
Side 1
Side 2
Top
Bottom
= 80 ft x 200 ft = 16,000 ft2
= 80 ft x 200 ft = 16,000 ft2
= 40 ft x 200 ft = 8,000 ft2
= 40 ft x 200 ft = 8,000 ft2
= 40 ft x 80 ft = 3,200 ft2
= 40 ft x 80 ft = 3,200 ft2
54,400 ft2