Carcass wrote:
Attachment:
GRE Each edge of the cube shown above has length n..png
Each edge of the cube shown above has length n. What is the perimeter, in terms of n, of quadrilateral \(ABDE\) ?
A. \(2n(1+\sqrt{2})\)
B. \(n \sqrt{2}\)
C. \(4n \sqrt{2}\)
D. \(4n\)
E. \(2n^2\)
Sides BD and AE are hypotenuse to right triangle CBD and FAE respectively.
Also BD = AE because it is a cube.
BD^2 = n^2 + n^2 --> 2n^2.
BD = 2n^2 under square root --> n√2 = AE as well.
Perimeter of quadrilateral ABDE in terms of n = n + n + n√2 + n√2.
= 2n + 2n√2 --> 2n(1+√2).
So, option A is the correct answer.