<span>For a craft project, two equilateral triangles are taped together to create a rhombus quadrilateral. In Euclidean geometry, a rhombus is a simple quadrilateral whose four sides all have the same length. Another name is equilateral quadrilateral, since equilateral means that all of its sides are equal in length.</span>
Since he starts off with 300 cards, the equation must have +300 units. As he purchases 40 each week, the rate of change is 40w. Since his goal is over 700, look for >700.
