This activity gives students an opportunity to use and develop their visualizing skills in conjunction with the knowledge of fractions. Students are given one large rectangle that is divided into ten smaller quadrilaterals and triangles in which they have to find what fractional part is represented by each of the ten numbered shapes. The Teachers' Notes page offers suggestions for implementation, discussion questions, ideas for extension and support.

This task is a reasonably straight-forward application of rigid motion geometry, with emphasis on ruler and straightedge constructions, and would be suitable for assessment purposes.

The goal of this task is to give students an opportunity to experiment with reflections of triangles on a coordinate grid. Students are not prompted in the question to list the coordinates of the different triangle vertices but this is a natural extension of the task.

In this problem students use spatial awareness and visualization to solve problems related to reflection (bilateral) symmetry. Learners are given three shapes and must assemble as many different but symmetrical composites as possible. Ideas for implementation, extension and support are included along with printable sheets of the shapes and a poster.

The goal of this task is to give students experience applying and reasoning about reflections of geometric figures using their growing understanding of the properties of rigid motions. In the case of reflecting a rectangle over a diagonal, the reflected image is still a rectangle and it shares two vertices with the original rectangle.

This activity is one in a series of tasks using rigid transformations of the plane to explore symmetries of classes of triangles, with this task in particular focusing on the class of equilaterial triangles. In particular, the task has students link their intuitive notions of symmetries of a triangle with statements proving that the said triangle is unmoved by applying certain rigid transformations.

This task examines some of the properties of reflections of the plane which preserve an equilateral triangle: these were introduced in ''Reflections and Isosceles Triangles'' and ''Reflection and Equilateral Triangles I''. The task gives students a chance to see the impact of these reflections on an explicit object and to see that the reflections do not always commute.

This activity is one in a series of tasks using rigid transformations of the plane to explore symmetries of classes of triangles, with this task in particular focussing on the class of isosceles triangles.

This interactive Flash applet gives students the opportunity to copy, create and extend repeating patterns utilizing two different triangles. Many patterns are possible since the angles in both are multiples of 30 degrees and the shorter sides are equal in length. The Teachers' Notes page includes suggestions for implementation, ideas for extension and support, and printable sheets (pdf).

This task presents students with some creative geometric ways to represent the fraction one half. The goal is both to appeal to students' visual intuition while also providing a hands on activity to decide whether or not two areas are equal.

This task provides a context for indentifying different ways of representing half of a rectangle.

This interactive activity adapted from the Wisconsin Online Resource Center challenges you to plan, measure, and calculate the correct amount of roofing material needed to reroof a house.

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.

This activity challenges students to visualize compound transformations of hexahedral dice to determine their right- or left-handedness. Ideas for implementation and support are included along with printable sheets of both types of dice.

This course has been designed to help students focus learning on specific areas of improvement. Unlike a typical college course where you would complete lessons in chronological order, this course allows you to focus on specific skills. Modules include: Arithmetic Review, Percents, Geometric Figures, Measurement, and Statistics

In this open investigation, students look for connections between shape and number by generating star patterns (regular n-grams) inside a circle. Ideas for implementation, extension and support are included along with a printable sheet (pdf) of circles with marked circumferences.

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.

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.