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A(1,-1), B(3,-4), C(6,-2), and D is an endpoint of rhombus. Determine distance B point to straight line from D and paralel with AC line?

 Dec 12, 2014

Best Answer 

 #1
avatar+23254 
+5

Point D is (4, 1).

Slope of line AC:  m  =  (-2 - -1)/(6 - 1)  =  -1/5

Line through D parallel to AC:  y - 1  =  (-1/5)(x - 4)  --->  x + 5y  =  9

Distance from point B to that line must have a slope perpendicular to that line and pass through (3, -4):

                 y + 4  =  5(x - 3)   --->  5x - y  =  19

Find the point where the two lines intersect:  x + 5y = 9  and 5x - y = 19   --->   (4, 1)

Find the distance from (3, -4) to (4, 1)   --->   d = √[ (4 - 3)² + (1 - -4)² ]  =  √26

 Dec 12, 2014
 #1
avatar+23254 
+5
Best Answer

Point D is (4, 1).

Slope of line AC:  m  =  (-2 - -1)/(6 - 1)  =  -1/5

Line through D parallel to AC:  y - 1  =  (-1/5)(x - 4)  --->  x + 5y  =  9

Distance from point B to that line must have a slope perpendicular to that line and pass through (3, -4):

                 y + 4  =  5(x - 3)   --->  5x - y  =  19

Find the point where the two lines intersect:  x + 5y = 9  and 5x - y = 19   --->   (4, 1)

Find the distance from (3, -4) to (4, 1)   --->   d = √[ (4 - 3)² + (1 - -4)² ]  =  √26

geno3141 Dec 12, 2014
 #2
avatar+130477 
0

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 Dec 12, 2014

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