![]() Similar shapes are identical in shape but not in size. If a shape can be transformed to another using enlargement, then the two shapes are similar. If a shape can be transformed to another using only translation, reflection and rotation, then the two shapes are congruent.Ĭongruent shapes have the same size, line lengths, angles and areas. The shape after it has been transformed is called the image. Shape transformations are changes done in the shapes on a coordinate plane. A geometry transformation is either rigid or non-rigid. The original shape before the transformation is called an object. A transformation changes the size, shape, or position of a figure and creates a new figure. A shape has rotational symmetry if, after you rotate less than one full turn, it is the same as the original shape. So this shape is said to have 180 rotational symmetry. Non-congruent shapes & transformations (Opens a modal) Practice. As this shape is rotated 360, is it ever the same before the shape returns to its original direction Yes, when it is rotated 180 it is the same as it was in the beginning. ![]() Read more about enlargements Images and Objects Use this immensely important concept to prove various geometric theorems about triangles and parallelograms. The length of the line drawn from the centre of enlargement to each point on the enlarged triangle is twice the length of the line drawn from the centre to the corresponding point on the original shape. The diagram below shows a triangle before (light blue) and after (dark blue) being enlarged: The enlarged shape is twice as large as the original shape. The diagram below shows a triangle before (light blue) and after (dark blue) being rotated: Each point on the rotated triangle is the same distance from centre of rotation as the corresponding point on the original shape.Īn enlargement makes a shape larger (or smaller).Īn enlargement resizes a shape about a point (called the centre of enlargement). Read more about reflections Rotation (or Turn)Ī rotation turns a shape around a point (called the centre of rotation). The idea is that the design could be continued infinitely far to cover the whole plane (though of course we can only draw a small portion of it). We might want to flip (reflect) a shape in a line. A tessellation is a design using one ore more geometric shapes with no overlaps and no gaps. We might be interested in sliding (translating) a shape. Here are some examples from transformations. ![]() The diagram below shows a triangle before (light blue) and after (dark blue) being reflected: Each point in the image (the reflection) is the same perpendicular distance from the line of reflection (in this case, the y-axis) as the corresponding point in the object. There are four types of transformations: translation, rotation, reflection and enlargement (or in simpler language: slide, turn, flip and resize). For the full list of videos and more revision. Read more about translations Reflection (or Flip)Ī reflection makes a shape a mirror image of itself.Ī reflection flips a shape in a line (called the line of reflection). GCSE Maths revision video on the topic of rotating shapes, using tracing paper, and describing transformations. The diagram below shows a triangle before (light blue) and after (dark blue) being translated: Each point on the shape moves the same direction and distance (shown by the arrow). The shape has moved three units to the left and six units down.A transformation can change a shape's position, orientation and its size.Ī translation is a slide of a shape (without rotating, reflecting or resizing it). ![]() Describing translationsĬolumn vectors are used to describe translations. A transformation is a way of changing the size or position of a shape.Įvery point in the shape is translated the same distance in the same direction. If students have not yet been introduced to rigid. Translation is an example of a transformation. A reflection is called a rigid transformation or isometry because the image is the same size and shape as the pre-image. Two figures A and B are congruent if one is the image of the other under a sequence of rigid transformations. A translation moves a shape up, down or from side to side but it does not change its appearance in any other way. Note that a translation is not the same as other geometry transformations including rotations, reflections, and dilations. ![]()
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