 Thales theorem
A web page and interactive applet illustrating Thales Theorem (the diameter of a circle always subtends a right angle to any point on the circumference). The applet shows a circle where the user can rotate the diameter and a move a point on the circumference. The applet continuously shows the resulting ...
Author(s): John Page

The Golden Rectangle
An interactive applet and associated web page that illustrate the properties the 'Golden Rectangle' whose sides are in the 'golden Ratio' of 1 : 1.618 : 1. The applet shows a golden rectangle whose vertices a re draggable. When dragged the rectangle changes to remain in the that shape. The web page ...
Author(s): John Page

Transversal
An interactive applet and associated web page that demonstrate the transversal, a line that crosses two other (usually parallel) lines. The applet shows two lines that are initially parallel, and a transversal line. All eight angles thus formed are shown. As you drag the transversal end points, you ...
Author(s): John Page

Trapezoid
A web page and interactive applet showing the definition and properties of a trapezoid. The applet shows a trapezoid where the user can drag any vertex. The other points then move in such a way that the figure remains a trapezoid at all times. A control to hide the details allows a classroom discussion ...
Author(s): John Page

Trapezoid median (midline, midsegment)
An interactive applet and associated web page that demonstrate the median line of a trapezoid (line linking midpoints of non-parallel sides). The applet shows a trapezoid with all vertices draggable. As you drag any vertex, the figure changes to remain trapezoid, and the median line id continually repositioned ...
Author(s): John Page

Triangle
An interactive applet and associated web page that introduce the concept of a triangle. The applet shows a triangle where the user can drag the vertices to reshape it. As it is being dragged a base and altitude are shown continuously changing. Demonstrates that the altitude may require the base to be ...
Author(s): John Page

Triangle centroid
A web page and interactive applet demonstrating the concept of the centroid of a triangle. The applet shows a triangle where the user can drag the vertices around. The centroid and the median lines that generate it are continuously moved as the user drags the vertices. By experimentation the user can ...
Author(s): John Page

Triangle Circumcenter
The applet shows a triangle which the user can resize by dragging any of its vertices. It shows the three perpendicular bisectors of the sides and the point where they intersect - the circumcenter. These track the changes in the triangle in real time. It shows that the circumcenter may lie outside the ...
Author(s): John Page

Triangle circumcircle
An interactive applet and associated web page that demonstrate the properties of the circumcircle of a triangle. The applet shows a triangle where the user can drag the vertices to reshape it. The circumcircle (the circle that passes through all vertices) is continuously updated as the triangle is resized. ...
Author(s): John Page

Triangle exterior angles
An interactive applet and associated web page that demonstrate the exterior angles of a triangle. The applet shows a triangle where the user can drag any vertex to reshape it. The exterior angles are shown and a running calculation shows that no matter how you change the triangle, the exterior angles ...
Author(s): John Page

Triangle Incenter
A web page and interactive applet demonstrating the concept of the incenter of a triangle. The applet shows a triangle where the user can drag the vertices around. The incenter and the angle bisector lines that generate it are continuously moved as the user drags the vertices. By experimentation the ...
Author(s): John Page

Triangle incircle
A web page and interactive applet demonstrating the concept of the incircle of a triangle - the largest circle the will fit inside a triangle. The applet shows a triangle where the user can drag the vertices around. The incircle is continuously adjusted as the user drags the vertices. By experimentation ...
Author(s): John Page

Triangle inequality
An interactive applet and associated web page that demonstrate the concept of triangle inequality. The applet shows a triangle where the vertices can be dragged to reshape the triangle It shows that no matter what you do, the longest side is always shorter than the sum of the other two. Applet can be ...
Author(s): John Page

Triangle interior angles
An interactive applet and associated web page that demonstrate the properties of the interior angles of a triangle. The applet shows a triangle where the user can drag the vertices to reshape it. As it is being changed, the angles are continually updated, along with an expression showing that they always ...
Author(s): John Page

Triangle midsegment
An interactive applet and associated web page that demonstrates the midsegment (midline) of a triangle. A triangle is shown that the user can reshape by dragging any vertex. As it is being dragged, the midline changes accordingly. From this can be seen that the midsegment is always parallel to the base ...
Author(s): John Page

Orthocenter of a triangle
A web page and interactive applet demonstrating the concept of the orthocenter of a triangle. The applet shows a triangle where the user can drag the vertices around. The orthocenter and the altitude lines that generate it are continuously moved as the user drags the vertices. By experimentation the ...
Author(s): John Page

Undecagon
A web page and interactive applet illustrating the properties of an undecagon (11 sided polygon). The applet shows an undecagon where the user can drag any vertex to reshape it. User can see that the interior and exterior angles are constant in a regular undecagon, but vary in an irregular version. ...
Author(s): John Page

Discovering Decimals
Students will learn about and work with decimals to the thousandths using their handhelds. They will read a web page, show they knowledge in an animation and finally test their knowledge in a game.
Author(s): Sarah Haver

Exploring Integers
Students will explore and implement the rules for adding, subtracting, multiplying, and dividing negative integers. This lesson would take place after each operation is explored individually.
Author(s): Cindy Carver

Exploring Literature and Weather through Chirps
In this lesson students will learn, explore and experience using crickets' chirps to calculate temperature. Students will also read both fiction and nonfiction stories and books about crickets.
Author(s): Beth Sanborn