- Students will prove a quadrilateral is a parallelogram given congruent opposite sides.
- Students will prove a quadrilateral is a parallelogram given congruent opposite angles.
- Students will prove a quadrilateral is a parallelogram given that the diagonals bisect each other.
- Students will prove a quadrilateral is a parallelogram if one pair of sides is both congruent and parallel.
IV.NotesonAssessment
- Check student work for accuracy. Offer feedback during presentations.
- Notice how the students demonstrate each point in their presentations.
Rhombi, Rectangles, and Squares
I.SectionObjectives
- Identify the relationship between the diagonals in a rectangle.
- Identify the relationship between the diagonals in a rhombus.
- Identify the relationship between the diagonals and opposite angles in a rhombus.
- Identify and explain biconditional statements.
II.ProblemSolvingActivity-Canyouproveit?
- To prepare this activity, you will need to draw either a rectangle or a rhombus on a coordinate grid. You can
have some be accurate and some close. - The students are going to need to figure out if the figure is a rectangle or a rhombus or does it just look like
one. - Students will be using the principles that they learned in the text to determine whether the figure is really a
rectangle or a rhombus. - Students can work in pairs or small groups on this activity.
- In a rectangle, the students should be pointing out that or proving that the diagonals are congruent.
- In a rhombus, the students should be proving or pointing out that the diagonals intersect at a right angle.
- Students can also use the angles of both figures and the relationship between the angles.
- Allow time for the students to investigate and prepare to prove what their figure is or is not.
- Then allow time for each group to present their discovery.
III.MeetingObjectives
- Students will use the relationship of the diagonals in a rectangle to prove whether a figure is a rectangle or not.
- Students will use the relationship of the diagonals in a rhombus to prove whether a figure is a rhombus or not.
- Students will explain their thinking to their peers.
IV.NotesonAssessment
- Listen to each group prove their figure.
- Challenge their thinking by asking questions.
- Be sure that student answers are clear and precise.
- Offer correction/feedback when needed.
5.6. Quadrilaterals