posted by Taylor .
if A(2,4) and B(3,1) and C(15,7) find the slope of the altitude from A to BC
A(2,4) , B(3,1), C(15,7).
The altitude is perpendicular to BC.
Therefore, it's slope is the negative reciprocal of BC.
m = (7-1) / (15-3) = 6/12 = 1/2=slope
m2 = -2/1 = -2 = Slope of altitude.