These are the topics related to the standard: Understand congruence and similarity using physical models, transparencies, or geometry software."
Here are some specific activities, investigations or visual aids picked out. Click anywhere in the grey area to access the resource.
Congruent Parts Use the colours to dissect the outlines into congruent parts.
Congruent Triangles Test your understanding of the criteria for congruence of triangles with this self-marking quiz.
Congruent Triangles Video Learn the conditions for two triangles to be congruent and then use this information to solve problems.
Similar Parts Use the colours to dissect the outlines into similar parts.
Click on a topic below for suggested lesson starters, resources and activities from Transum.
- Enlargements When areas and volumes are enlarged the results are far from intuitive. Doubling the dimensions of a rectangle produces a similar shape with four times the area! Doubling the dimensions of a cuboid produces a similar shape with eight times the volume! The activities provided are intended to give pupils experiences of dealing with enlargements so that they better understand the concept and are able to produce diagrams, make models and answer questions on this subject. Once positive integer scale factors have been mastered the notion of fractional and negative scale factors await discovery!
- Shape This topic is aimed at the learners of basic geometry, which is the study of size, shape and position. More than other areas of mathematics this topic helps pupils to learn about the definitions and properties of basic shapes. There are many activities provided ranging from simple shape naming games to applying more advanced formulas and theorems. The most popular activities however are those involving pupils to count the number of triangles or rectangles in patterns and come up with effective strategies and justifications for their answers. The work pupils produce for this topic can make very good display material. The use of colour can enhance the diagrams and make the learning environment more conducive to study. There are many connections between the mathematics of shape and Art. There are fascinating works of art based on symmetry, tessellations and transformations.
- Symmetry This topic covers line symmetry and rotational symmetry. The innate appeal of symmetry can be found in our reactions to finding symmetry in natural objects, such as precisely formed crystals or seashells. Symmetry in art is another source of delight. Understanding the mathematics of symmetry is the focus of this topic. Accurately drawing the reflection of an object requires an understanding of the relative positions of reflected points. Defining the position of the mirror line is important to find the position and orientation of the reflection. The Wrapping Paper lesson starter makes it clear that for rotational symmetry, the position of the centre of rotation is very important. Work on this topic can produce some excellent display work!
- Transformations A transformation in mathematics is an operation performed on a shape (or points) which changes the view of that shape (or points). This topic includes four transformations namely reflection, translation, rotations and enlargement. A reflection can best be described as the mirror image of a shape in a given line (which acts as the mirror). After reflection the shape remains the same size but the orientation is the mirror image of the original. The transformation known as a translation can be thought of as a movement or shift in position. The size and orientation of the shape remains the same but the position on the plane changes. A rotation can be described as turning. This transformation is defined by the angle of turning and the centre of rotation (the point which does not move during the turning). Finally enlargement is the term we use when a shape increases in size but maintains the same shape. The shape after enlargement is defines as being similar to the shape before enlargement. His use of the word similar has a precise mathematical meaning. All of the angles in the enlarged shape are the same as the angles in the original shape and the lengths of the sides are in the same proportion. An enlargement is defines by the scale factor of the enlargement and the centre of enlargement. We use the term enlargement even if the shape becomes smaller (a scale factor between minus one and one). A negative scale factor will produce an enlarged mirror image of the original shape.
