Francisco E. answered 05/31/14
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Francisco; Civil Engineering, Math., Science, Spanish, Computers.
The orthocenter of a triangle is the point of intersection of the altitudes or heights drawn from each of the three vertices. The height will be perpendicular to the side where it is taken.
A = (0,-2); B = (4,-2); and C = (-2,-8)
so: let's get the slope of a side: AC which will be (-8+2)/(-2-0) = 3, so the slope of the perpendicular is -(1/3) and the equation of the height line from B will be ( y+2) = -(1/3)*(x-4) => (3y+6)= -x+4, then the first equation of a line will be
3y + x = -2
now for the line from point A to line BC we have slope of BC = (-8+2)/(-2-4) = 1 and the slope of the perpendicular is -1, the equation from the point A will be (y+2) = -(x-0) so the equation is y+x=-2
y+x=-2
solving this two equations because they will have (x,y) as the point where they meet will give to us
y=0 and x = -2, the orthocenter is at (-2,0)
CHECK!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!