prove that the points (0,0), (5,5), (-5,5) are the vertices of a right angled triangle.
Let the vertices be A(0,0); B(5,5) and C(-5,5).Remember that in a right triangle Pythagoras theorem will be followed.Also for an isosceles triangle two sides must be of the same length.By distance formula: The triangle is clearly isosceles as AB = AC.
Also,AB2 + AC2 = 50 + 50 = 100 = 102 = BC2
So, by converse of pythagoras theorem, , given triangle is a right triangle in which, angle A is 900