Learn to jack up a car with a scissor lift. By that I mean, learn to take any quadrilateral and decide whether that shape is, in fact, a parallelogram.
Geometry 5(A) investigate patterns to make conjectures about geometric relationships, including angles formed by parallel lines cut by a transversal, criteria required for triangle congruence, special segments of triangles, diagonals of quadrilaterals, interior and exterior angles of polygons, and special segments and angles of circles choosing from a variety of tools
Geometry 6(B) prove two triangles are congruent by applying the Side-Angle-Side, Angle-Side-Angle,Side-Side-Side, Angle-Angle-Side, and Hypotenuse-Leg congruence conditions
Geometry 6(E) prove a quadrilateral is a parallelogram, rectangle, square, or rhombus using opposite sides, opposite angles, or diagonals and apply these relationships to solve problems.