[b]The objectives of this activity[/b]:[br]With the GeoGebra app:[br]1. you will become familiar with some of the tools used in GeoGebra.[br]2. you will explore what you can and can't change once you have constructed a figure.[br]3. You will work with 2 of the three undefined terms, point & line, in order to illustrate some postulates.[br]With the follow-up questions:[br]1. You will review and extend your understanding of the postulates and definitions you encountered[br]2. You will review the vocabulary used in this activity.[br]3. You will use the Applet to make some observations and write some conclusions.[br][br]What you should do in your notebook:[br]1. Add any new vocabulary to your vocabulary section.[br]2. Write down questions and correct answers for any questions that you weren't sure about and/or got incorrect.[br]3. Keep track of new observations and facts that helps you extend your understanding of the material covered.[br]

[size=150][b]Part A - what you will do on the applet below[/b][br]Directions:[br]***once you have drawn something always go back to the [b]move tool[/b] (or hit esc on keyboard) in order interact with what you have on the screen. Move your figures around. Notice what you can and can't change***[br][br]A[/size][size=150]. Construct a diameter[br]1. Construct a circle using the [b]Circle with Center through point tool.[/b] [br]2. Use the [b]line tool[/b] to construct a line that contains the circle's center and the point on the circle.[br]3. This line contains the diameter & 2 radii ( 1 diameter = 2 radii)[br][br]B. Use Show/hide tool to illustrate the diameter[br]1. Select [b]Show/hide tool [/b]and then the line you constructed, then select the [b]segment tool.[br][/b]2. You should have 2 pts on the circle, they are the endpoints of a diameter. With the [b]segment tool[/b] still selected; select those two points to construct a diameter.[br][br]Use the [b]point tool[/b] and plot two points, then use the [b]line tool[/b] to construct a line.[br] [/size][size=150] What you have just done is illustrated the following [color=#ff0000]postulate: [u]"Through 2 points there is exactly one line"[/u][/color][br] Definition, [b][color=#980000]postulate -A geometric statement whose truth is assumed without a proof[/color][/b][/size][b][color=#980000].[br][/color][color=#0000ff][br]Clear your screen[br][br][/color][/b][size=150]C. Explore - use any tools you want to[br]1. Construct a circle again.[br]2. See if it is possible to construct a diameter another way.[br][br][br][br] there[br]1. Use the [b]ray tool[/b] to draw a ray, the first point that is illustrated is its endpoint.[br]2. Use the [b]segment tool[/b] to draw a segment.[br]3. Use [b]Segment with Given length tool[/b] to draw another segment.[br]4. Use the [b]midpoint tool[/b] to locate a midpoint on your two segments.[br]  a. use the [b]distance/length tool[/b] to measure the length of the two segments formed by the midpoint.[br] b. Construct a line. Can you get a midpoint for your line?[br][br][b][color=#0000ff]Clear your screen[br][br][/color][/b]C. Circles constructed two ways. Vocabulary: center, point on a circle, radius.[br]1. Construct your first circle using the [b]Circle with Center through point* tool[/b] - *that point is on the circle.[br]2. Construct your 2nd circle using the [b]Circle: Center* & radius tool[/b] - *the center is point in the interior of the circle.[br]Use the move tool to explore what you can and can't change about the 2 circles.[br]3. First, delete your 2nd circle. Construct a [color=#980000][b]radius [/b][/color]for your 1st circle using the [b]segment tool.[br][/b]4. Construct a 2nd radius for that circle but this time use [b]Segment with Given length tool[/b] [u]And instead of writing in a specific value[/u] enter the endpoints' name of the first radius for example AB - the capital letters side by side is the symbol that stands for: "the length of segment AB".[br]Do this once more. You will now have 3 radii (plural for radius) for your circle.[br]5. Use the [b]distance or length tool[/b] to get the length of all three radii.[br][br][b][color=#0000ff]Clear your screen[br][br][/color][/b]D. One more postulate.[br]1. use the [b]line tool[/b] to construct 2 lines that intersect.[br]2. Use the [b]intersect tool[/b] to get their point of intersection.[br]You have illustrated the [color=#ff0000]postulate: "[u]if two lines intersect, then they intersect in exactly one point.[/u]"[/color][br][br][/size]