What is the formula for the total surface area of a triangular prism?

[Howard]

I know the one for a rectangular prism is 2(l+w) + 2lw. (You may have been taught 2l+2w + 2lw)

I'm not even sure that one is actually in existence, after searching through Google.

 

[loogie]

3lw + bh
I think.

l = length of side
w = width
b = base of triangle on the end
h = height of triangle on teh end

he's right.
|
|
|
v

 

[Talon]

SA = (bh1+bh2+bh3) + 2(1/2bh)

 

[Howard]

I am correct in assuming that this only works for triangular prisms whose base is an equilateral triangle?

 

[Howard]

Thanks Talon, I'll try that.

 

[zzzz]

add the areas of all sides..

 

[Talon]

Yucky,

Check out this site. Just select triangular prism.

http://www.shodor.org/interactivate/activities/sa_volume/index.html

 

[MereMortal]

Yucky, your formula for the surface area of a rectangular prism is missing a variable. The term 2lw is ok, as it has units of area, but the term 2(l+w) has units of length. It should be of the form 2d(l+w), where d is the depth, or SA=2(lw+ld+wd).

As for the triangular prism, it would be helpful to know what variables you can measure. Talon's formula is fine, if you have all those values, but the formula becomes nastier if only allowed, say three variables for a scalene prism.

 

[Mday]

do you mean an irregular 3d triangular object?

prism means the bases of the object are the same. that is, the top triangle and the bottom triangle are the same shape orientation and stuff. and those vertical lines are perpendicular (normal) to the plane of the base (triangles)

otherwise, the term oblique is injected.

say, you twist the damn prism, it's nearly improbably to find it unless you have the proper "equation" of each "surface" from which you use the calculus.

if it's just some triangle, and you "extrude" it in one direction perpendicular to the plane of the triangle, then you have a regular trianglar prism, and you get, the areas of each side, and 2x the area of a base (since both are the same).

 

[MereMortal]

You may be correct. I was under the impression that a prism was just two polygonal faces in parallel planes, with their sides being joined by parallelograms. If that's not the case, then there is no such thing as a scalene (triangular) prism.

Anyway, what fun is a prism as you define it?