{"id":11469,"date":"2022-07-12T12:41:20","date_gmt":"2022-07-12T07:11:20","guid":{"rendered":"https:\/\/mathemerize.com\/?p=11469"},"modified":"2022-07-12T12:54:38","modified_gmt":"2022-07-12T07:24:38","slug":"prove-that-the-sum-of-the-squares-of-the-sides-of-a-rhombus-is-equal-to-the-sum-of-the-squares-of-its-diagonals","status":"publish","type":"post","link":"https:\/\/mathemerize.com\/prove-that-the-sum-of-the-squares-of-the-sides-of-a-rhombus-is-equal-to-the-sum-of-the-squares-of-its-diagonals\/","title":{"rendered":"Prove that the sum of the squares of the sides of a rhombus is equal to the sum of the squares of its diagonals."},"content":{"rendered":"
Let the diagonals BD and AC of the rhombus ABCD intersect each other at O.<\/p>\n
Since the diagonals of the rhombus bisect each other at right angles.<\/p>\n
\\(\\therefore\\)\u00a0 \\(\\angle\\) AOB = \\(\\angle\\) BOC = \\(\\angle\\) COD = \\(\\angle\\) DOA = 90<\/p>\n
and\u00a0 AO = CO, BO = OD<\/p>\n
Since AOB is a right triangle angled at O, therefore,<\/p>\n
\\({AB}^2\\) = \\({OA}^2\\) + \\({OB}^2\\)<\/p>\n
Since AO = CO, BO = OD,<\/p>\n
\\(\\implies\\) \\({AB}^2\\) = \\(({1\\over 2}{AB})^2\\) + \\(({1\\over 2}{BD})^2\\)<\/p>\n
\\(\\implies\\)\u00a0 \\(4{AB}^2\\) = \\({AC}^2\\) + \\({BD}^2\\)\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 ……….(1)<\/p>\n
Similarly, we have :<\/p>\n
\\(4{BC}^2\\) = \\({AC}^2\\) + \\({BD}^2\\)\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 ……..(2)<\/p>\n
\\(4{CD}^2\\) = \\({AC}^2\\) + \\({BD}^2\\)\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 ……..(3)<\/p>\n
\\(4{AD}^2\\) = \\({AC}^2\\) + \\({BD}^2\\)\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0………(4)<\/p>\n
Adding all the equations above, we get<\/p>\n
\\({AB}^2\\) + \\({BC}^2\\) + \\({CD}^2\\) + \\({DA}^2\\) = \\({AC}^2\\) + \\({BD}^2\\)<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":" Solution : Let the diagonals BD and AC of the rhombus ABCD intersect each other at O. Since the diagonals of the rhombus bisect each other at right angles. \\(\\therefore\\)\u00a0 \\(\\angle\\) AOB = \\(\\angle\\) BOC = \\(\\angle\\) COD = \\(\\angle\\) DOA = 90 and\u00a0 AO = CO, BO = OD Since AOB is a right …<\/p>\n