Using Geometer's Sketch Pad

Using Geometer's Sketch Pad

Creating a line segment:

1) To access Geometer's Sketch Pad, go to the apple in the left hand of the screen and drag down to GSP. Release the mouse.

2) You will see the GSP on the screen. Click anywhere on the screen to get rid of the logo.

3) The first thing we are going to do is make a point. You do this by going to the toolbar on the left hand side of the screen and highlight the "point" symbol. Now use the mouse to put a point on your blank screen. We want to find out the name of this point. We can label the point by going to the toolbar and highlighting the "hand" symbol. Now click on your point and your point should have a label.

4) Now you are going to make a line segment. Remember, a line segment has two endpoints. Go to the toolbar and create another point on your screen. Go ahead and give it a label using the directions above. Once you have two points that are labeled, go to the toolbar and click on the arrow. This will allow us to use the different menus. With the arrow, click on one of your points. What happened? Click on that same point again. What happens now? The arrow tool allows us to highlight different things on our screen. If you want to highlight more than one item, you will have to hold down the SHIFT key. We are going to highlight both points. (This means they should both be "darker" now.)

5) Make sure that your arrow is still highlighted on your tool bar. We are now going to go to the top of the screen titled CONSTRUCT. Use your mouse to select CONSTRUCT and drag down to SEGMENT. This will create a line segment using your two points as its endpoints. Click on the white screen so that nothing is highlighted.

6) You have now created a line segment. Try to make another on your own.

Creating a line:

1) Go to the FILE menu and drag down to NEW SKETCH. This puts a clean "sheet" of paper on the screen. Your other "sheet" is still there and you can still have access to it. We are now going to see what a true line looks like. Go to the toolbar and highlight the line segment but do not let go of the mouse. You should see a couple of different items you can choose. Highlight the one that you think looks like a line and release the mouse. What happens? Use the mouse to highlight the arrow tool again. Use the arrow to move your line around. To do this click on one of the points on the line and drag it around. Why can we not see the beginning or end? Try creating another line on your own.

Creating a ray:

1) Go to the FILE menu and drag down to NEW SKETCH. We are now going to see what a true ray looks like. Go to the tool and highlight the line segment but do not let go of the mouse. You should see a couple of different items you can choose. Highlight the one that you think looks like a ray and release the mouse. Now go to the blank screen and click with your mouse. What happens? Use the mouse to highlight the arrow tool again. Use your arrow to move your ray around. You can do this by clicking on the point on the ray and moving it around. Why can we see the beginning and not the end?

Creating an angle:

1) Go to the FILE menu and drag down to NEW SKETCH. We are going to create an angle. You can do this by creating two line segments that meet at a common endpoint (vertex). Highlight the line segment on the tool bar (remember to hold down and drag across to the one that looks like a line segment.) Create a line segment by clicking on the blank screen and dragging across to a stopping point. Now create another line segment by starting at one of the endpoints you created and dragging across to another stopping point. After you have your angle, label the three points using the hand tool.

2) We are going to measure the angle and try to create an acute, right, obtuse, and straight angle. We want the computer to measure the angle's opening by using its internal protractor. To do this, first highlight the arrow tool on the tool bar. Click on a blank portion of the screen using your arrow tool to ensure nothing is highlighted. We are now going to highlight the points. Remember that your vertex will have to be in the middle when you highlight your three points. For example, if you have angle ABC, you can highlight A, then B, then C, or you can highlight C, then B, then A. Remember to hold down the shift key!

3) Once all three points are highlighted, go to the menu up at the top of the screen and select MEASURE. Drag your mouse down to ANGLE. When you select ANGLE you will get the measure of your angle. Once you have done that, click on a blank portion of the screen with your mouse. This will ensure that nothing else is highlighted.

4) Was your angle acute, right, obtuse, or straight? Let us try to create each type of angle. If you notice, you can pick one of your endpoints, if nothing else is highlighted, on your angle and move it around. What happens to the angle measure. As you can see, as your angle's openness changes, so does your angle measure. Create an acute, right, obtuse, and straight angle. Refer back to your definitions if you need to. You can label each angle by clicking on the hand tool and using the mouse to "drag" out a box to type in. Once the box is there, you can type inside it. Be sure to observe other student's work.