Determine the minimum amount of packaging needed to completely cover a triangular prism Oblerone bar with these dimensions: length 22.5 cm; triangular face

A right triangular prism has 3 rectangular faces.

If each of the edges of the triangular base measures 4.5cm,

and the length (the height) of the prism is 22.5cm,

the 3 rectangular faces (sides of the box) are rectangles,

22.5cm long and 4.5cm wide.

Each face has a surface area of (22.5cm)(4.5cm)=101.25 square centimeters.

The total lateral surface area for the 3 rectangular sides of the box is

3(101.2 square centimeters)=303.75 square centimeters.

If the triangular faces of the box are triangles

with a base measuring 4.5cm and a height measuring 4.0cm,

the surface area of each triangular face is

(1/2)(4.5cm)(4.0cm)=9 square centimeters.

The surface area of the two triangular faces adds up to

2(9 square centimeters)=18 square centimeters.

The total surface area for the box is

303.75 square centimeters + 18 18 square centimeters= 321.75 18 square centimeters,

and that rounds up to highlight 322 square centimeters.

NOTE:

The answer above is the one your teacher wants,

but there is a problem with this problem.

An equilateral triangle with sides measuring 4.5cm

would have a height of approximately 3.9cm.

The Pythagorean theorem says so.

However, the 4.0cm value makes the calculations easier.

i would say c is the best answer, hope it's right!

good luck! =)

cutie~

each side has a different length.  

step-by-step explanation: