Parallelogram Template

Parallelogram Lab
Use GeoGebra to complete the following investigation. [b]BE SURE to move the vertices and sides of this parallelogram around after completing each step in order to help you make more informed conjectures[/b]: [br][br]1) Measure and display the lengths of all 4 sides. What, if anything, do you notice? Describe in detail. [br]2) Construct the midpoint of segment AC (even though you haven’t constructed segment AC yet.) Label this point “E”. [br]3) Construct segments with lengths AE, BE, CE, & DE. Then measure and display their lengths. What do you notice? Describe in detail. [br]4) Measure & display the measures of the following angles: Angle BAE, EAD, ADE, EDC, DCE, ECB, CBE, EBA. What do you notice? Describe in detail. [br]5) Measure display just one of the four angles you see with vertex E. [br]6) Construct polygon (triangle) ABC. Then reflect this polygon about diagonal AC.[br]7) Use GeoGebra to “UNDO” step (6) and step (5). Now construct polygon (triangle) DBA. Then reflect this polygon about diagonal DB. [br][br]Questions to answer/consider: [br][br]1) Are opposite sides of a parallelogram congruent? [br]2) Are opposite angles (ENTIRE ANGLES—like angle DAB & angle DCB) of a parallelogram congruent?[br]3) Do the diagonals of a parallelogram bisect EACH OTHER?[br]4) Does a diagonal of an parallelogram bisect a pair of opposite angles? If so, how many diagonals do this? [br]5) Are the diagonals of a parallelogram perpendicular? [br]6) Are the diagonals of a parallelogram congruent?[br]7) Does either diagonal of a parallelogram serve as a line of symmetry? If so, how many?

Parallelograms (I)

[color=#000000]Please use these applets to help you complete the [/color][i][color=#0000ff]Parallelogram Investigation[/color][/i][color=#000000] questions given to you at the beginning of class. [/color]
Sides of a Parallelogram
Interior Angles of a Parallelogram
Diagonals of a Parallelogram

Quadrilateral Angle Theorems

Interact with the app below for a few minutes.  [br]Then, answer the questions that follow.  [br][br]Be sure to change the locations of this quadrilateral's vertices each time [i]before[/i] you drag the slider!
Into how many non-overlapping triangles were we able to split this quadrilateral?
What is the sum of the measures of the interior angles of [i]each triangle[/i]?
Use your responses from the two questions above to [b]determine the sum of the measures of the interior angles of this quadrilateral. [/b]
What is the [b]sum of the measures of the exterior angles[/b] of this quadrilateral?

Parallelogram: Theorem 1

Interact with the applet below for a few minutes. [br]Then, answer the questions that follow. [br][br]Feel free to move the BIG WHITE POINTS anywhere you'd like! [br][color=#ff00ff]You can also adjust the size of the pink angle by using the slider. [/color]
1.
What special type of quadrilateral was formed in the first half of your sliding-the-slider? How do you know this?
2.
What else can you conclude about this special type of quadrilateral? Be specific!
3.
Write a 2-column, paragraph, or coordinate geometry proof of what you've informally observed here. (Hint: If you choose a 2-column or paragraph proof, this proof will involve a pair of congruent triangles!)
Quick Demo: 0:00 sec to 0:33 sec (BGM: Andy Hunter)

Information