The midpoints of the sides of any quadrilateral with perpendicular diagonals form a rectangle. All non-self-crossing quadrilaterals tile the plane by repeated rotation around the midpoints of their edges. Similarities preserve planes, lines, perpendicularity, parallelism, midpoints, inequalities between distances and line segments. The twelve midpoints to edges of the cube form a hexagram. The proof of the property on midpoints is best done for the hyperbola formula 213. This diminishing radius produces a series of involute midpoints (i.e. located on a spiral). The midpoints between those four times of year are the four lesser directions. The intervals above all have the same length on them, with the "midpoints" actually midway. In general road distance signs are measured to city midpoints. It touches the sides at its midpoints. Alternatively, the difference between points can be used instead of evaluating f(x,y) at midpoints. At this point, the voltage between the two midpoints (B and D) will be zero. The program allows the determination of the midpoints and midsegments of objects. He showed some good pace, fighting consistently for midpoints scoring positions. Midpoints of sides are mapped onto midpoints and centroids on centroids.