Open Tab Labeled P-Gram 1 Located at the Bottom Left of the Screen

Let’s discover some properties about Parallelograms. As we work with the P-gram, remember….Think SAD (sides, angles, and diagonals) with a smile!

Open tab labeled P-gram 1 located at the bottom left of the screen.

Why do we call this a Parallelogram?

Let’s verify: Highlight , go to the Measure menu and choose slope. Do the same for the other 3 segments.

**Write out the property in words:

The of a parallelogram are .

3. Let’s stay focused on the sides:

What is another side relationship that is found in a parallelogram?

Verify with measurements. ( Hint: Highlight the desired part of the figure and

go to the Measure menu)

**Write out the property in words:

The of a parallelogram are .

4. Let’s move on to angles:

Open tab labeled P-gram 2 located at the bottom left of the screen.

What is one angle relationship that you think might be found in a parallelogram?

How can you verify this? Show your verification below. Remember when you choose an angle to choose the three points with the vertex in the middle!

**Write out the property in words:

The of a parallelogram are .

5. Ok, stay with the angles. There is another angle relationship… do you see it?

What do you think it is?

Verify this mathematically:

+ =

+ =

+ =

+ =

**Write out the property in words:

The of a parallelogram are .

6. Time to work with diagonals:

Open tab labeled P-gram 3 located at the bottom left of the screen.

Highlight two opposite vertices, go to the Construct menu and click on segment.

Click on white space. Do this again for the other two opposite vertices.

Your diagram should look like this:

Let’s name the intersection of the diagonals. Highlight and , go to the Construct

menu and click on Intersection.

What do you think the intersection point does to the diagonals?

Verify this using the Measure menu.

= =

= =

**Write out the property in words:

The of a Parallelogram each other.

Properties of a Parallelogram

Copy the 5 properties of Parallelograms that you discovered in this lab:

1.

2.

3.

4.

5.

Will these properties hold for all Parallelograms? Open tab labeled P-gram 4.

Click on point A and move it around to change the shape of the parallelogram.

Now test the properties above by measuring the angles, segments, and diagonals

by highlighting and using the Measure menu.

What do you think? Do the properties hold for ALL Parallelograms?