Question

Graham carves a block of wood shaped like a cube with a square pyramid on top. How much paint will Graham need to paint the toy? Enter your answer in the box.

Answer 1

1080 cm^2

Explanation:

∴ Given:

Graham carves a block of wood shaped like a cube with a square pyramid on top.

∴To Find:

How much paint will Graham need to paint the toy?

∴Solve:

Base on the given:

`S=5a^2+4ah\cdot(1)/(2)`

=
`5\cdot12^2+4\cdot12\cdot15\cdot(1)/(2)`

`=1080cm^2`

Hence
`1080cm^2` of paint is needed.

~lenvy~

Answer 2

Divide the box into two parts for easy way answer

For cube:-

• Side=a=12cm

TSA

• 6a²
• 6(12)²
• 6(144)
• 864cm^2

Cancel one side area

• TSA=864-144=720cm^2

For triangular pyramid:-

Area of one base

• 0.5(Base)(Height)
• 0.5(12)(15)
• 6(15)
• 90cm^2

Area of four sides=90(4)=360cm^2

Total surface area:-

• 720+360
• 1080cm^2