ZOJ Problem Set - 1769
You work for an art store that has decided to carry every style and size of drafting triangle in existence. Unfortunately, sorting these has become a problem. The manager has given you the task of organizing them. You have decided to classify them by edge length and angles. To measure each triangle, you set it on a large sheet of very accurate graph paper and record the coordinate of each point. You then run these three points through a computer program to classify the triangles according to:
Scalene: no equal sides
Acute: all angles under 90
Of course, sometimes you make mistakes entering the data, so if you input points that do notform a valid triangle, your program should tell you.
One triangle is described per line. Each line has six measurements taken to the nearest 0.001 in the order:
x1 y1 x2 y2 x3 y3
The final line of input will contain only a -1.
None of the test sets contain non-right angles in the range 88-92 degrees, nor do any of the test sets include any non-equal side lengths for one triangle within 0.01 of one another.
You will output one line for each triangle, which will contain two words:
<length classification> <angle classification>
Not a Triangle
The final line of your output file will be:
End of Output
10.000 10.000 10.000 20.000 20.000 10.000
Source: Mid-Atlantic USA 2003