Triangle $ABC$ has vertices $A(2, 3),$ $B(1, -8)$ and $C(-3, 2).$ The line containing the altitude through $A$ intersects the point $(0, y).$ What is the value of $y$?
BC has the slope [ -8 - 2 ] / [ 1 - - 3] = -10 / 4 = -5/2
The altitude through A will have the slope (2/5)
Writing an equation for a line containg this altitude, we have
y =(2/5) (x - 2) + 3
When x = 0, y = (2/5)(0 -2) + 3 = -4/5 + 3 = 11/5 = 2.2
+0 
