SOLUTION: Geometry. For the floor plans given in exercise 27, determine whether the side through the points (2, 3) and (11, 6) is perpendicular to the side through the points (2, 3) and (-

Algebra ->  Points-lines-and-rays -> SOLUTION: Geometry. For the floor plans given in exercise 27, determine whether the side through the points (2, 3) and (11, 6) is perpendicular to the side through the points (2, 3) and (-      Log On


   

Question 78573: Geometry. For the floor plans given in exercise 27, determine whether the side
through the points (2, 3) and (11, 6) is perpendicular to the side through the points
(2, 3) and (-3, 18).
Answer by checkley75(3666) About Me  (Show Source):
You can put this solution on YOUR website!
we need to find the slopes of these two lines to prove if they are perpendicular. Thus:
(6-3)/(11-2)=3/9=1/3 for the slope through the first set of points.
the formula for this line is:
3=2/3+b
b=3-2/3
b=7/3 or
y=x/3+7/3 (red line)
(18-3)/(-3-2)=15/-5=-3 this slope is the negative reciprical of the first slope.
3=-3*2+b
3=-6+b
b=3+6
b=9
y=-3x+9 (green line)
Therefore these lines are perpendicular as proven by the following graph-
+graph%28+300%2C+300%2C+-10%2C+10%2C+-10%2C+10%2C+y+=+x%2F3+%2B7%2F3%2C+y+=+-3x+%2B9%29+ (graph 300x300 pixels, x from -10 to 10, y from -10 to 10, of TWO functions y = x/3 +7/3 and y = -3x +9).