SOLUTION: Here is a solution by MathLover1: http://www.algebra.com/tutors/students/your-answer.mpl?question=1205618 I would never in a million years trust her solution, given her reputat

Algebra ->  Customizable Word Problem Solvers  -> Geometry -> SOLUTION: Here is a solution by MathLover1: http://www.algebra.com/tutors/students/your-answer.mpl?question=1205618 I would never in a million years trust her solution, given her reputat      Log On

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Question 1205620: Here is a solution by MathLover1:
http://www.algebra.com/tutors/students/your-answer.mpl?question=1205618
I would never in a million years trust her solution, given her reputation on this forum. Can someone either verify, or provide the right solution?


Found 2 solutions by MathLover1, ikleyn:
Answer by MathLover1(20849) About Me  (Show Source):
Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
.

Point X is the intersection of the two diagonals TW and UV of the cubical box illustrated.
The shortest distance from point T to point Z is 4sqrt%283%29 cm.
Find the area in square centimetres of triangle XYZ.
~~~~~~~~~~~~~~~~~~~~~~~

It is well known fact that if "a" is the length of the edge of a cube,
then the longest 3D-diagonal of the cube, connecting the opposite corners (vertices)
is  a%2Asqrt%283%29.


In this problem, you are given that the longest 3D-diagonal of the cube is 4%2Asqrt%283%29 cm.
It means that the edge of the cube is 4 cm long.


OK.  To find the area of triangle XYZ, we need to know its height (its altitude).
This altitude is the hypotenuse of the right angled triangle with the legs a/2 = 2 cm
and a = 4 cm, so the altitude of the triangle XYZ is

    h = sqrt%282%5E2+%2B+4%5E2%29 = sqrt%2820%29 = 2%2Asqrt%285%29 cm.


Now the area of the triangle XYZ is half the product of its base a = ZY = 4 cm by the altitude h

    area%5BXYZ%5D = %281%2F2%29%2A4%2A2%2Asqrt%285%29 = 4%2Asqrt%285%29 = 8.944 cm^2  (approximately).    ANSWER

Solved.