UPSC One
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2014 · Q82

Consider the following statements:

  1. 1Let ABCD be a parallelogram which is not a rectangle. Then 2(AB^2 + BC^2) ≠ AC^2 + BD^2.
  2. 2If ABCD is a rhombus with AB = 4 cm, then AC^2 + BD^2 = n^3 for some positive integer n.

Which of the above statements is/are correct?

Elementary MathematicsGeometry
  1. A1 only
  2. B2 only
  3. CBoth 1 and 2
  4. DNeither 1 nor 2

Explanation

Parallelogram law gives 2(AB^2+BC^2) = AC^2+BD^2 always, so 1 is false; for a rhombus AC^2+BD^2 = 4(4^2) = 64 = 4^3, so 2 is true.