Question

ABCD is a quadrilateral. Prove that AB+BC+ CD + DA AC + BD​

Answer 1

Answer:-

This question is based on the triangle inequality theorem that the sum of lengths of two sides of a triangle is always greater than the third side.

Now visually identify that the quadrilateral ABCD. It is divided by diagonals AC and BD into four triangles.

Now, take each triangle separately and apply the above property and then add L.H.S and R.H.S of the equation formed.