1. Jul 2, 2010

Atran

Hi, How can I measure one solid angle of a cuboid, at least a non-sphere shape?

Thanks...

2. Jul 2, 2010

Atran

A cuboid with the sides (a), (b) and (c).
I think the total steradians of it is 3602=(129600*π)/360=720π

V = a*b*c
V = (4π(r3))/3

((3*a*b*c)/4π)(1/3) = r
((3*a*b*c)/4π)(2/3) = r2

((3*a*b*c)/4π)(2/3) * 720π = A

Is that procedure correct?

Last edited: Jul 2, 2010
3. Jul 3, 2010

Atran

I wrote incorrect above, right?
If a circle and a rectangle have totally 360 degrees, therefore a sphere has the same amount of degrees (4π) as a cuboid has.

So this should be incorrect ((3*a*b*c)/4π)(2/3) * 720π = A),
and the correct one should be: ((3*a*b*c)/4π)(2/3)) * 4π = A

All I want is to measure one point's degrees in a cuboid.

Last edited: Jul 3, 2010
4. Jul 3, 2010

g_edgar

Don't use 360^2. That would be stedegrees or something. Not steradians.