LET X BE THE LENGTH OF AN EDGE OF THE CUBE. WE CAN FIND THE LENGTH...

35. Let x be the length of an edge of the cube. We

can find the length of

BC by first finding the length

of

CD.

CD must be

x

since it is the hypotenuse

of a 45-45-90 triangle with legs of length x.

Using the Pythagorean theorem, BC can be calculated:

AB = CD = x

, so BC – AB = x

– x

.

If we factor this expression and simplify, x(

–

) ˜ x(1.7 –