Posted by **Knights** on Thursday, April 4, 2013 at 11:57am.

What is the cosine of the angle between two adjacent faces of a regular tetrahedron? (We define the angle between two intersecting planes as the angle between two intersecting lines, one in each plane, such that each line is perpendicular to the line at which the planes intersect.)

I don't understand....it is not cosine 60, so could someone help?

## Answer This Question

## Related Questions

- Math - Someone please explain these! The angle between two planes is defined as ...
- Math - Someone please explain these! The angle between two planes is defined as ...
- Math - Someone please explain these! The angle between two planes is defined as ...
- Math - Let AB and CD be two lines intersecting at point O. Let OP be the ...
- Math - Let AB and CD be two lines intersecting at point O. Let OP be the ...
- geometry - if i know one angle between the diagonals at intersecting point , how...
- Math - Perry draws two planes, K and L, as shown. Which statement is true? ...
- Trigonometry - Two radar stations are 50 miles apart. Both are tracking the same...
- Math - Which statement(s) is/are true?Select one of the options below as your ...
- Geometry - If two non parallel lines are perpendicular to two other straight ...

More Related Questions