document.write( "Question 1073145: Prove that parallelogram is a rhombus if its diagonals bisect at right angles
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Algebra.Com's Answer #688008 by KMST(5328)\"\" \"About 
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The diagonals of a parallelogram bisect each other,
\n" ); document.write( "splitting the parallelogram into 4 triangles.
\n" ); document.write( "If they intersect at right angles,
\n" ); document.write( "those 4 triangles are right triangles.
\n" ); document.write( "If the length of the diagonals are D and d,
\n" ); document.write( "All 4 of those right triangles have legs of length
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\n" ); document.write( "With a pair of congruent sides flanking congruent right angles,
\n" ); document.write( "they are congruent right triangles,
\n" ); document.write( "and their corresponding other sides (hypotenuses)
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\n" ); document.write( "So, the 4 sides of the parallelogram (the 4 hypotenuses)
\n" ); document.write( "are congruent, and a parallelogram with 4 congruent sides
\n" ); document.write( "is called a rhombus.
\n" ); document.write( "(It could even be the particular type of rhombus that we call a square).
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