The construction of the perpendicular bisector of a line segment is one of the most common in plane geometry and it is undertaken here. In addition to giving students a chance to work with straightedge and compass, the problem uses triangle congruence both to show that the constructed line is perpendicular to AB and to show that it bisects AB.

This task is for instruction purposes. Part (b) is subtle and the solution presented here uses a "dynamic" view of triangles with two side lengths fixed. This helps pave the way toward what students will see later in trigonometry but some guidance will likely be needed in order to get students started on this path.

An interactive applet and associated web page that demonstrate the concept of a convex polygon - one where all interior angle are less than 180 degrees. The applet shows an irregular convex polygon initially. The user can drag any vertex, change the number of sides in the range 3..99, and make it regular or irregular. When the polygon is convex, the polygon is so flagged. It is shown that regular polygons are always convex. The goal is to show through experimentation what the concept of convexity really means. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

These games support student development of the concept of ordered pairs as they play to win each game.

An interactive applet and associated web page that describe the concept of the coordinate plane (Cartesian Plane). The applet shows the plane, its axes, origin and related controls. The user can drag a point around and see the coordinates change, and click anywhere to create new points. The origin can be dragged to emphasize or eliminate certain quadrants. The grid, axis pointers and coordinates can be turned on and off. The coordinate display can be turned off to permit class exercises and then turned back on the verify the answers. The applet can be printed as it appears on the screen to make handouts. The web page has a narrative description of the concept. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

An interactive applet and associated web page that describe the concept of a point in coordinate geometry. The applet show one point initially, but clicking anywhere adds more. As the points are dragged, the coordinates are seen to change. The grid, axis pointers and coordinates can be turned on and off. The coordinate display can be turned off to permit class exercises and then turned back on the verify the answers. The applet can be printed as it appears on the screen to make handouts. The web page has a narrative description of the concept, including the definitions of abscissa, ordinate, coordinates, ordered pair. The applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

An interactive applet and associated web page that demonstrate the concept of coplanar objects - those that lie in the same plane. The applet presents two planes. In one plane there are two rectangles that can be dragged around and which lie in the same plane always. The other is a rectangle that can be dragged but always lies in a plane orthogonal to the first. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

An interactive applet and associated web page that provide step-by-step instructions on how to copy a line segment using only a compass and straightedge. The animation can be run either continuously like a video, or single stepped to allow classroom discussion and thought between steps. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

An interactive applet and associated web page that provide step-by-step instructions on how to divide a line segment into any number of equal parts, using only a compass and straightedge. The applet starts with a given line segment and ends with that segment divided into n parts. In the applet n=5, but the construction works for any n. The animation can be run either continuously like a video, or single stepped to allow classroom discussion and thought between steps. The text on the page has printable step-by-step instructions. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

An interactive applet and associated web page that provide step-by-step instructions on how to copy a given triangle using only a compass and straightedge. The animation can be run either continuously like a video, or single stepped to allow classroom discussion and thought between steps. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

An interactive applet and associated web page that demonstrate the corresponding angles that are formed where a transversal crosses two lines. The applets cycles through the four possible pairs of angles when in animation mode. By dragging the three lines, it can be seen that the angle pairs are congruent only when the lines are parallel. When not in animated mode, there is a button that cycles through each the four pairs of angles. The text on the page discusses the properties of the pairs of corresponding angles both in the parallel and non-parallel cases. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

This short video and interactive assessment activity is designed to teach first graders about counting rectangles, squares, and triangles in composite figures.

This challenging problem and brainteaser gives first graders an opportunity to compose and decompose squares.

This short video and interactive assessment activity is designed to teach third graders about counting vertices and sides in various shapes.

An interactive applet and associated web page that demonstrate the properties of a cube. A 3-D cube is shown in the applet which can be interactively manipulated using the mouse. Research has shown that some younger students have difficulty visualizing the parts of a 3D object that are hidden. To help with this, the student can rotate the cube in any axis simply by dragging it with the mouse. It can also be 'exploded' - where a slider gradually separates the faces to reveal the ones behind. The cube can also be made translucent so you see through it to the other side. Applet can be enlarged to full screen size for use with a classroom projector, and printed to make handouts. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

An interactive applet that allows the user to graphically explore the properties of a cubic equation. Specifically, it is designed to foster an intuitive understanding of the effects of changing the 4 coefficients in the function. The applet shows a large graph of a quadratic (ax^3 + bx^2 +cx + d) and has four slider controls, one each for the coefficients a,b,c and d. As the sliders are moved, the graph is redrawn in real time illustrating the effects of these variations. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Included are the support materials for Grade 2 Blended Learning Math - Unit 6.0: Geometry - Introduction:
- YouTube video on introducing grade 2 geometry
- Manipulatives and Templates to support Unit 5
- Assessment and Evaluation for Unit 5

Included are the support materials for Grade 2 Blended Learning Math - Unit 6.1: Geometry - Attributes:
- YouTube video on geometric attributes plus bonus video on animal colours and shapes
- Manipulatives and Templates to support Unit 6
- Assessment and Evaluation for Unit 6

Included are the support materials for Grade 2 Blended Learning Math - Unit 6.2: Geometry - Sorting According to Shape Attributes:
- YouTube video on sorting according to shape attributes
- Manipulatives and Templates to support Unit 6
- Assessment and Evaluation for Unit 6