Question

A triangular prism is covered with foil label The label does not cover the two ends. How much foil is necessary to cover the prism

Answer 1

Answer:

The required foil is about  $2ls+lb$ sq units.

Step-by-step explanation:

Given:

A triangular prism covered with foil.

To Find:

If two ends are not covered how much foil is required.

Solution:

The triangular prism has total of 5 faces  as

two side faces ............... Rectangular shape

one bottom face.............rectangular shape

two side faces............ triangular face.

(Refer the attachment for diagram)

Area of triangle =$1/2(base*height)$

Now there  2 traingles so

Total are for triangle =$base * height$

Area for bottom rectangle,

=length *breadth

$=l*b$

Area for 2 side rectangles,

=2*(length * breadth)

=2*(l*S)

$=2*l*S$

Hence required area =total area -area of triangle

(As triangles are presented at both ends) and as per condition.

$=(2ls+lb+bh)-bh$

$=2ls+lb$.