Helping students gain understanding and self-confidence in
algebra. descartes123 wrote:prove that the triangle with its
summits P(-2,-1), Q(6,1) and R(3,4) is right-angle. descartes123
wrote:The thing is that in this case we have to use a formula,
describing a distance between to points. let's say if we have
two points M1(x1,y1) and M2(x2,y2). and you have to use a
distance formula.