Please explain! First grade math. There is still a process! There are n straight lines on the plane. Try to determine how many congruent angles they have at most. Continuous internal angle

Suppose there are (n/2-a) horizontal straight lines and (n/2+a) vertical straight lines.

Then the number of angles = 4 * (n/2-a) (n/2+a) = n 2-4a 2.

When a=0, the value of the above formula is the largest, that is

When the number of horizontal and vertical straight lines is equal, the most angles can be formed.

Among these angles, n/2 angles on the right side of the same vertical line can be defined by

C(2, n/2) For isoseismic lines, C(2, n/2)=n*(n-2)/4.

There are n/2 vertical lines * * * in total, and each vertical line can form 4 groups, so it can form the logarithm of the congruence angle.

=n^2/(n-2)/2

The internal angle and internal dislocation angle of the same side are not calculated, and the method is similar.

For the problem of finding laws, we must first find out which parts have changed and according to what laws.