The vertices of a triangle ABCare A(1,1),B(-3,4),C(2,-5).The equation to the altitude trrough the vertex A is

5x-9y+4=0

To find a line u need 2 things only..

here u can get slope and point.

as said perpendicular  from   A

perpendicular ot the line BC..

slope of BC (say m) = -5-4 / 2-(-3)  = -9/5

slope of the line req. (say n) = 5/9   i.e  (-1/m)

and the point is A..

get the line.