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.