A web page and interactive applet showing the ways to calculate the area of a rhombus. The user can drag the vertices of the rhombus and the other points change automatically to ensure it remains a rhombus. A grid inside the shape allows students to estimate the area visually, then check against the actual computed area. The text on the page gives three different ways to calculate the area with a formula for each. The applet uses one of the methods to compute the area in real time, so it changes as the rhombus is reshaped with the mouse. A companion page is http://www.mathopenref.com/rhombus.html showing the definition and properties of a rhombus 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 a right angle (those equal to 90 deg). The applet presents an angle (initially 90 deg) that the user can adjust by dragging the end points of the line segments forming the angle. As it changes it shows the angle measure and a message that indicate which type of angle it is. There a software 'detents' that make it easy capture exact angles such as 90 degrees and 180 degrees The message and angle measures can be turned off to facilitate classroom discussion. The text on the page has links to other pages defining each angle type in depth. 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 task provides a good opportunity to use isosceles triangles and their properties to show an interesting and important result about triangles inscribed in a circle: the fact that these triangles are always right triangles is often referred to as Thales' theorem. It does not have a lot of formal prerequisites, just the knowledge that the sum of the three angles in a triangle is 180 degrees.

The result here complements the fact, presented in the task ``Right triangles inscribed in circles I,'' that any triangle inscribed in a circle with one side being a diameter of the circle is a right triangle. A second common proof of this result rotates the triangle by 180 degrees about M and then shows that the quadrilateral, obtained by taking the union of these two triangles, is a rectangle.

An interactive applet and associated web page that demonstrate the three types of triangle: acute, obtuse and right. The applet shows a triangle that is initially right (one angle 90 degrees) which the user can reshape by dragging any vertex. There is a message changes in real time while the triangle is being dragged that tells if the triangle is an acute, right or obtuse triangle and gives the reason why. By experimenting with the triangle student can develop an intuitive sense of the difference between these three classes of triangle. 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.

Students solidify their understanding of the terms "circumference" and "rotation" through the use of LEGO MINDSTORMS(TM) NXT robotics components. They measure the circumference of robot wheels to determine how far the robot can travel during one rotation of an NXT motor. They sharpen their metric system measurement skills by precisely recording the length of a wheel's circumference in centimeters, as well as fractions of centimeters. Through this activity, students practice brainstorming ways to solve a problem when presented with a given scenario, improve their ability to measure and record lengths to different degrees of precision, and become familiar with common geometric terms (such as perimeter and rotation).

This short video and interactive assessment activity is designed to teach third graders an overview of rotational symmetry.

Suppose you see a nickel rolling on the sidewalk. Imagine a pen traced the path of one fixed point on the coin as it rolled. A curve would be created. This curve is called a roulette.

Check out these great video/curricular resources for Grade 2. The ROVER videos all indicate the curriculum outcomes that they address.

ROVER (Recommended Online Video Education Resources) is a video streaming service for Saskatchewan teachers and students in the PreK-12 education system. It is managed and maintained by the Saskatchewan Ministry of Education. ROVER is a video-on-demand service that provides teachers and students with the convenience of immediate access to streamed, educational videos that support curricula.

This site also offers all of the curriculum documents for all grade levels.

If you are unable to access the site, it may be because a Saskatchewan Ministry of Education Blackboard login is required. All students have an Edonline account, so contact your child's school or the Ministry of Education’s Support Desk at 1-866-933-8333 or email at stans@gov.sk.ca for login information. Your child's student number will be required.

Check out these great video/curricular resources for Grade 3. The ROVER videos all indicate the curriculum outcomes that they address.

ROVER (Recommended Online Video Education Resources) is a video streaming service for Saskatchewan teachers and students in the PreK-12 education system. It is managed and maintained by the Saskatchewan Ministry of Education. ROVER is a video-on-demand service that provides teachers and students with the convenience of immediate access to streamed, educational videos that support curricula.

This site also offers all of the curriculum documents for all grade levels.

If you are unable to access the site, it may be because a Saskatchewan Ministry of Education Blackboard login is required. All students have an Edonline account, so contact your child's school or the Ministry of Education’s Support Desk at 1-866-933-8333 or email at stans@gov.sk.ca for login information. Your child's student number will be required.

This task uses geometry to find the perimeter of the track. Students may be surprised when their calculation does not give 400 meters but rather a smaller number.

The goal of this task is to model a familiar object, an Olympic track, using geometric shapes. Calculations of perimeters of these shapes explain the staggered start of runners in a 400 meter race.

Same But Different is a powerful routine for use in math classrooms. The activity of same but different is an activity where two things are compared, calling attention to both how they are the same and how they are different.

This apparent paradox is the beauty of the activity. It is important to notice the word BUT. Instead of making a choice – am I going to prove that these are the same or am I going to prove that they are different – students are considering how two items can be both. This is a critically important distinction.

Not same OR different, rather same BUT different.

There are categories for addition/subtraction, early numeracy, multiplication/division, measurement, place value, fractions, ratios, geometry, algebra, and high school math.

An interactive applet and associated web page that shows how triangles that have two sides and their included angle the same must be congruent. The applet shows two triangles, one of which can be reshaped by dragging any vertex. The other changes to remain congruent to it and the two sides and the included angle are outlined in bold to show they are the same measure and are the elements being used to prove congruence. The web page describes all this and has links to other related pages. 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 showing how the SAS similarity test works. Two similar triangles are shown that can be resized by dragging. The other triangle adjusts to remain similar and the side-angle-side elements are highlighted to show how they are involved in this test of similarity. (two sides in proportion and the included angle the same). The web page describes all this and has links to other related pages. 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 reference book project at http://www.mathopenref.com.

An interactive applet and associated web page that shows that side-side-angle is not enough to prove congruence, because two triangles can meet the condition. The applet shows two triangles, one of which can flip between the two possible configurations that both meet the SSA criteria, showing it is insufficient. The web page describes all this and has links to other related pages. 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 shows how triangles that have all 3 sides the same length must be congruent. The applet shows two triangles, one of which can be reshaped by dragging any vertex. The other changes to remain congruent to it and the three sides are outlined in bold to show they are the same length and are the elements being used to prove congruence. The web page describes all this and has links to other related pages. 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 showing how the SSS similarity test works. Two similar triangles are shown that can be resized by dragging. The other triangle adjusts to remain similar and the angle-angle-angle elements are highlighted to show how they are involved in this test of similarity. (all three corresponding sides in the same proportion). The web page describes all this and has links to other related pages. 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 reference book project at http://www.mathopenref.com.

This is the first version of a task asking students to find the areas of triangles that have the same base and height, and is the most concrete.

This is the second version of a task asking students to find the areas of triangles that have the same base and height. This presentation is more abstract as students are not using physical models.