This is a collection of 110 (in binary) 2D geometry problems. CircumscribedCircle x1 y1 x2 y2 x3 y3 Find out the circumscribed circle of triangle (x1, y1) − (x2, y2) − (x3, y3). These three points are guaranteed to be non-collinear. The circle is formatted as (x, y, r) where (x, y) is the center of circle, r is the radius. InscribedCircle x1 y1 x2 y2 x3 y3 Find out the inscribed circle of triangle (x1, y1)−(x2, y2)−(x3, y3). These three points are guaranteed to be non-collinear. The circle is formatted as (x, y, r) where (x, y) is the center of circle, r is the radius. TangentLineThroughPoint xc yc r xp yp Find out the list of tangent lines of circle centered (xc,yc) with radius r that pass through point (xp,yp). Each tangent line is formatted as a single real number ‘angle’ (in degrees), the angle of the line (0 ≤ angle < 180). Note that the answer should be formatted as a list (see below for details). CircleThroughAPointAndTangentToALineWithRadius xp yp x1 y1 x2 y2 r Find out the list of circles passing through point (xp, yp) that is tangent to a line (x1, y1) − (x2, y2) with radius r. Each circle is formatted as (x, y), since the radius is already given. Note that the answer should be formatted as a list. If there is no answer, you should print an empty list. CircleTangentToTwoLinesWithRadius x1 y1 x2 y2 x3 y3 x4 y4 r Find out the list of circles tangent to two non-parallel lines (x1, y1) − (x2, y2) and (x3, y3) − (x4, y4), having radius r. Each circle is formatted as (x,y), since the radius is already given. Note that the answer should be formatted as a list. If there is no answer, you should print an empty list.
2/3 CircleTangentToTwoDisjointCirclesWithRadius x1 y1 r1 x2 y2 r2 r Find out the list of circles externally tangent to two disjoint circles (x1, y1, r1) and (x2, y2, r2), having radius r. By “externally” we mean it should not enclose the two given circles. Each circle is formatted as (x, y), since the radius is already given. Note that the answer should be formatted as a list. If there is no answer, you should print an empty list. For each line described above, the two endpoints will not be equal. When formatting a list of real numbers, the numbers should be sorted in increasing order; when formatting a list of (x,y) pairs, the pairs should be sorted in increasing order of x. In case of tie, smaller y comes first. Input There will be at most 1000 sub-problems, one in each line, formatted as above. The coordinates will be integers with absolute value not greater than 1000. The input is terminated by end of file (EOF). Output For each input line, print out your answer formatted as stated in the problem description. Each number in the output should be rounded to six digits after the decimal point. Note that the list should be enclosed by square brackets, and tuples should be enclosed by brackets. There should be no space characters in each line of your output. Sample Input CircumscribedCircle 0 0 20 1 8 17 InscribedCircle 0 0 20 1 8 17
3/3 TangentLineThroughPoint 200 200 100 40 150 TangentLineThroughPoint 200 200 100 200 100 TangentLineThroughPoint 200 200 100 270 210 CircleThroughAPointAndTangentToALineWithRadius 100 200 75 190 185 65 100 CircleThroughAPointAndTangentToALineWithRadius 75 190 75 190 185 65 100 CircleThroughAPointAndTangentToALineWithRadius 100 300 100 100 200 100 100 CircleThroughAPointAndTangentToALineWithRadius 100 300 100 100 200 100 99 CircleTangentToTwoLinesWithRadius 50 80 320 190 85 190 125 40 30 CircleTangentToTwoDisjointCirclesWithRadius 120 200 50 210 150 30 25 CircleTangentToTwoDisjointCirclesWithRadius 100 100 80 300 250 70 50 Sample Output (9.734940,5.801205,11.332389) (9.113006,6.107686,5.644984) [53.977231,160.730818] [0.000000] [] [(112.047575,299.271627),(199.997744,199.328253)] [(-0.071352,123.937211),(150.071352,256.062789)] [(100.000000,200.000000)] [] [(72.231286,121.451368),(87.815122,63.011983),(128.242785,144.270867),(143.826621,85.831483)] [(157.131525,134.836744),(194.943947,202.899105)] [(204.000000,178.000000)]