Here are the questions:
I have posted a link there to this thread so the OP can see my work.Question on analytic geometry about slopes?
Find the interior angle of the triangle with vertices (2, -5), (6,2), (4,1)
It must 180 degrees when calculated but stuck on the solution.
The line through (-2, y) and (2, 10) is perpendicular to a line through (-3, -7) and (5, -5) find y.
The formula will be like y2-y1 / x2- x1
and formula for angle tan m2-m1/1+m1(m2)
solution of the answer is appreciated.