3
$\begingroup$

So for 2D angles (radians), the measure of the angle is equal to length of the subtended arc of the unit circle.

Can we define 3D angles to be the area subtended by the angle on the unit sphere?

For example, the 3D angle measure of one corner of a cube is $1/8 \times 4\pi = 1/2\pi$

$\endgroup$
3
$\begingroup$

solid angle/steradian are the terms used for this concept you can read more about them here http://en.wikipedia.org/wiki/Solid_angle

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.