The question is asking which of the following does not have side that are parallel. So which of them have lines that would never touch if they were never ending lines.
Answer: the number that are at the left side of the decimal is the whole numbers and the ones at the right are like the ones less than the whole numbers
That would be John Stillwell's aptly titled Mathematics and its History. It teaches you the math along with the history, and is excellent.
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41. This is a kite quadrilateral, whose<span> four sides can be grouped into two pairs of equal-length sides that are adjacent to each other, because FI=NI, FE=NE, as you can calculate from the given coordinates. However, this is not a rhombus, because the four side lengths are not all equal.
44. The rhombus is centered at (0,0). The two diagonals are evenly divided by the center. SO=OL=SL/2=2a/2=a. S(-a,0), L(a,0). FO=PO=FP/2=4b/2=2b. F(0,2b), P(0,-2b).
45. </span>P(a-b, c).<span>The y coordinate of P is the same as the y coordinate of (-b,c), which is c, because the two points are on the same horizontal line. The x coordinate of P - the x coordinate of (0,0) is the same as the x coordinate of (-b,c) - the x coordinate of (-a,0). So x=-b-(-a)=a-b. P(a-b, c).
46. Suppose the four coordinates of the kite are A(x,y), C(x+2a,y), B(x+a, y+b), D(x+a, y-b). The midpoint of AB is (x+a/2, y+b/2). midBC is (x+3a/2, y+b/2). midCD is (x+3a/2, y-b/2), midAD is (x+a/2. y-b/2). ABCD is a rectangle.</span>
