Posted by Sue on Sunday, January 13, 2013 at 4:34pm.
Find the slope of altitude to line AT the coordinates are A(7,0) and T (9,7)

Math high school  Reiny, Sunday, January 13, 2013 at 4:48pm
find the slope of AT
then the altitude is at right angles to it, so its slope is the negative reciprocal of the slope of AT