Cube Shape Question

Question

 

 

Which of the following shapes is it NOT possible for a cross section of a cube to take.

 

equilateral triangle                     rectangle

 

square                                      octagon

 

rhombus                                   isosceles triangle

 

 

thanks

Answer 1

The only one of those shapes it's impossible to create is an octagon. It's hard to explain why in text, so check this website for illustrations:

 

http://www.learner.org/courses/learningmath/geometry/session9/solutions_c.html#c1

 

Remember that a rhombus is just a quadrilateral with four congruent sides, so a square is also a rhombus.