Because one slope is positive while the other slope is a negative reciprocal of it.
For example: 2*-1/2 = -1
If the product is -1 then the lines are perpendicular to one another.
Take any two lines and look at their slopes. -- If the slopes are equal, then the lines are parallel. -- If the product of the slopes is -1, then the lines are perpendicular.
You have to know the slopes of both lines. -- Take the two slopes. -- The lines are perpendicular if (one slope) = -1/(the other slope), or the product of the slopes equals to -1.
Are perpendicular to one another.
perpendicular
If the product is -1 then the lines are perpendicular to one another.
It is always -1.
-1
When the perpendicular lines are horizontal and vertical.
2
Take any two lines and look at their slopes. -- If the slopes are equal, then the lines are parallel. -- If the product of the slopes is -1, then the lines are perpendicular.
Are perpendicular.
You have to know the slopes of both lines. -- Take the two slopes. -- The lines are perpendicular if (one slope) = -1/(the other slope), or the product of the slopes equals to -1.
Are perpendicular to one another.
In that case, the product of the slopes is equal to minus 1.
Perpendicular lines * Two lines that create an angle of 90 degrees and the product of their slopes is -1.
Slopes of perpendicular lines will be opposite reciprocals. This means that the slopes have opposite signs and that one is 1/ the other. For example, 2 and -1/2.