Notes: Include multi-step proofs and algebraic problems built upon these concepts. The inclusive definition of a trapezoid will be utilized, which defines a trapezoid as “A quadrilateral with at least one pair of parallel sides.” Examples of theorems include but are not limited to: A diagonal divides a parallelogram into two congruent triangles. Opposite sides/angles of a parallelogram are congruent. The diagonals of a parallelogram bisect each other. If the diagonals of a quadrilateral bisect each other, then the quadrilateral is a parallelogram. If the diagonals of the parallelogram are congruent then the parallelogram is a rectangle. Additional theorems covered allow for proving that a given quadrilateral is a particular parallelogram (rhombus, rectangle, square) based on given properties.