Geometers Sketch pad

Step 1: Open Sketch pad

Use this to select items Use this to draw a point Use this to draw a circle Use this to draw a line Use this to write something or label items Use this to find out information about items Step 2: Get to know Sketch pad

Step 3: Use Sketch pad Use the point tool to draw a few points on the page Use the line tool to draw a few lines on the page Use the circle tool to draw a few circles on the page

Your page should look something like this.

Use the select tool to select different items on your page. When an item is selected it will have a colored circle around it

Step 4: Draw an angle Open a new file Use the line tool to draw an angle. Use the select tool to select the points on your angle in the order that you would use to name them. Remember to have the vertex in the middle. Make sure you do not have a line selected.

Step 4: Measure an angle Click on measure in the tool bar at the top of your screen. Then click on angle.

The computer will measure the angle and display it in a text box

Step 5: Measuring the angles in a triangle Make your angle into a triangle by adding an extra line. Measure the other two angles of your triangle

Step 6: Calculate the degrees in a triangle Click on measure in the tool bar at the top of your screen. Then click on calculate.

Add the three angles of your triangle

Step 7: Draw each of the polygons listed in the table and calculate their interior angles.