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Ertices of a parallelogram ABCD taken in order are A(3, 6), B(5, 10) and C(3(1) the co-ordinates of the fourth vertex D.2. length of diagonal BD.3. equation of side AB of the parallelogram ABCD. |
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Answer» Answer: We have A(3,6);B(5,10);C(3,2) are the GIVEN 3 vertices of parallelogram ABCD. Let D(a,b) be the coordinates of the fourth vertex, Now, we know that DIAGONALS of a parallelogram bisect each other, So, coordinates of mid point of BD = coordinates of mid point of AC. (5+a/2 ,10+b/2) = (3+3/2, 6+2/2) using mid point formula X = x1+x2/2 : y = Y1 +y2/2 (5+a/2 ,10+b/2) = (3,4) 5+a/2= 3 and 10+b/2 = 4 5+a = 6 and 10+b = 8 A = 1 and b = -2 So, coordinates of vertex d are : D(1,-2) We know that distance between points (x1,y1) and (x2,y2) is Distance = √(x2-x1)² + (y2-y1)² Now, BD = √(5-1)²+ (10+2)2² = √16+144 = √160 =4√10 units We know that equation of line segment joining (x1,y1) and (x2,y2) is y-y1/x-x1 = y2-y1/x2-x1 so, equation of line segment joining A(3,6) and B(5,10) is y-6/x-3 = 10-6/5-3 Y-6/x-3 = 4/2 Y-6/x-3 = 2 Y-6 = 2x -6 Y-2x = 0 Y = 2x Hope it helps you ..... |
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