Dynamic kite

A kite is a quadrilateral with two pairs of adjacent equal sides. Move B to change one side length. Move C to change the other side length.
Can you make
  • a rhombus? 
  • a square?
  • a non-convex quadrilateral?
Part of the textbook Measuring the World: Mathematics for Elementary and Middle School Teachers by Susan Addington and David Dennis. Copyright 2009.