Using Geometer’s Sketchpad to Prove a Figure is a
Parallelogram and another Figure is a Rectangle
Prove a Figure is a Parallelogram
1) In Geometer’s Sketchpad Select Graph, Then Define Coordinate
System. Make sure Graph, Snap Points is checked.
2) Using the point tool, plot and label the following points A(0,0),
B(1,4), C(4,1) and D(3,-3).
3) Verify your point placement by selecting the point and selecting
measure, coordinates.
4) Connect the points using the line segment tool.
5) Using the formula for slope show opposite sides are parallel. Select
Measure, Calculate and then input your calculation in the calculator.
Select OK and your formula will display in GSP. Label the segment
this calculation applies to by selecting the Text Box Tool and typing
the segment (Slope of AB =) your calculations in Geometer’s
Sketchpad using the Text Box Tool.
6) Check your calculations by selecting the segment and then selecting
measure then slope.
7) Using the distance formula calculate the lengths of opposite sides.
You can use the calculate tool under the measure menu. In the
calculator, select Function then sqrt then put your equation in the
formula. Your calculation will appear in a text box. Set this equal to
the segment using the Text Box Tool.
8) Check your calculation by selecting the endpoints of the segment and
measure, then distance.
9) If opposite sides are parallel and equal in length, then the figure is a
parallelogram. Using the Text Box Tool document whether the figure
is a parallelogram or not. Save your GSP file, but leave the file open.
10)
Open Open Office Impress to create a PowerPoint. The first
slide should be a title page “Proving Parallelograms and Rectangles.
Be sure to include your name.
11)
Insert a 2nd new slide and in Geometer’s Sketchpad under the
Edit Menu choose select all, then copy. Switch to Impress and paste
your GSP document into the slide.
Prove a Figure is a Rectangle
12)
In Geometer’s Sketchpad Select New Sketch, Select Graph,
Then Define Coordinate System. Make sure Graph, Snap Points is
checked
13)
Using the point tool, plot the following points A(-6,2), B(-3,5),
C(3,-1) and D(0,-4).
14)
Verify your point placement by selecting the point and selecting
measure, coordinate.
15)
Connect the points using the line segment tool.
16)
Using the formula for slope show opposite sides are parallel.
Select Measure, Calculate and then input your calculation in the
calculator. Select OK and your formula will display in GSP. Label
the segment this calculation applies to by selecting the Text Box Tool
and typing the segment (Slope of AB =) your calculations in
Geometer’s Sketchpad using the Text Box Tool.
17)
Check your calculations by selecting the segment and then
selecting measure then slope.
18)
Using the distance formula calculate the lengths of opposite
sides. You can use the calculate tool under the measure menu. In
the calculator, select Function then sqrt then put your equation in the
formula. Your calculation will appear in a text box. Set this equal to
the segment using the Text Box Tool.
19)
Check your calculation by selecting the endpoints of the
segment and measure, then distance.
20)
Check to see if the angles formed between adjacent sides are
right angles by checking to see if adjacent sides are perpendicular.
Using the Measure Calculate function Multiply the slope of adjacent
sides to see if the slopes are opposite reciprocals. If their product is
equal to -1 then the lines are perpendicular and angles are right angles.
21)
If opposite sides are parallel and equal in length, and adjacent
sides are perpendicular then the figure is a rectangle. Using the Text
Box Tool, document whether the figure is a rectangle or not. Save
your GSP file, but leave the file open.
22)
Open Open Office Impress to create a PowerPoint. The first
slide should be a title page “Proving Parallelograms and Rectangles.
Be sure to include your name.
23)
Insert a 2nd new slide and in Geometer’s Sketchpad under the
Edit Menu choose select all, then copy. Switch to Impress and paste
your GSP document into the slide.
24)
Email your Impress document to DebraLuce@irvingisd.net.
Please name your file with your first and last name.