Prove that in a parallelogram, the sum of the squres of the diagonals is equal otthe four times the sum of the square of three conterminos edges.

Prove that the sum of the squares of the diagonals of a rhombus is equal to the sum of the squares of the sides.

Prove that three times the sum of the squares on the sides of a triangle is equal to four times the sum of the square on the medians of the triangle.

Prove that the sum of the squares of the diagonals of parallelogram is equal to the sum of the squares of its sides.

Prove that three xx the sum of the squares of the sides of a triangle is equal to four xx the sum of the squares of the medians of the triangle.

Prove that three xx the sum of the squares of the sides of a triangle is equal to fourxx the sum of the squares of the medians of the triangle.

Prove that the sum of the squares of the sides of a rhombus is equal to the sum of the squares of its diagonals.

Three xx the sum of square of the sides of a triangle is equal to four xx the sum of the square of the medians of the triangle.

prove by vector method that the sum of the squares of the diagonals of a parallelogram is equal to the sum of the squares of its sides.