Look to the left hand side and click on the T at the bottom of the tool bar. Click on Incircle. Place curser on the page and left click mouse to create first point. Drag the line to create the second point and left click mouse. You have now constructed a line. Move curser up/down/left/right to create the third vertex of the triangle. You should now see three vertices and a a light bluie circle on the outside of the gray triangle. Notice that the circle touches all three vertices of the triangle. As you animate a vertex, notice how the area of the blue circle changes as the area nd overall size and shape of the triangle changes. You did a wonderful job constructing your circumcircle!