Pythagoras theorem

Without using Pythagoras's theorem, show that the points A(1, 2), B(4, 5) and C(6, 3) are the vertices of a right-angled triangle.

(Pythagoras's Theorem) Prove by vector method that in a right angled triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides.

(Pythagoras's Theorem) Prove by vector method that in a right angled triangle,the square of the hypotenuse is equal to the sum of the squares of the other two sides.

(Pythagoras's Theorem) Prove by vector method that in a right angled triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides.