Intersection C makes CF perpendicular to CB intersection C, with point C as the origin, CF as the X axis, CB as the Y axis and CD as the Z axis, and establishes a spatial rectangular coordinate system, namely: A(- root number 3, 1, 1), B (0,2,0) and C (0,0,0).

Therefore, vector AD(- root number 3, 1, 1,) vector AB(- root number 3, 3, 0), vector BE(0, 0, 2), let the normal vector n(X, y, z) of plane ABE, then the equations can be simultaneous:

-radical number 3 * x+3y = 0；; 2Z=0。 So the vector n is (root number 3*Y, y, 0), let Y= 1, and the vector n is (root number 3, 1, 0).

So cos; = (-radical number 3* radical number 3+1*1+0 *1)/(2 * radical number 5)=- radical number 5/5.

Since the angle formed is obviously acute, the sine value of the angle formed is 5/5 of the root sign.

You can borrow a science math class to read. The space vector is very simple, but the calculation is a little more troublesome. After the coordinate system is successfully established, as long as you are careful not to make mistakes, it will generally be right. This is the most rigid method, but it is very practical ~