Students will understand that:

• a scale diagram is an enlargement or a reduction of a given diagram.
• two polygons are similar if they have the same shape, but not necessarily the same size.
• similar polygons have congruent corresponding angles and proportional corresponding sides
• we can use scale diagrams and the properties of similar triangles to solve problems involving lengths that cannot be measured properly.
• A shape has line symmetry if it can be divided into two congruent parts, so that the parts coincide when the shape is folded along a line of symmetry; this is called the line of reflection.
• A shape has a rotational symmetry if it coincides with itself in less than one full turn about its centre.

Essential Questions:

What is a scale diagram? What are enlargement and reduction? What is a scale factor?

What are proportional sides? What are corresponding lengths, angles and sides?

What are similar polygons? What is a line or reflection and/or a line of symmetry?

What is equidistant? What is rotational symmetry? What is the centre of rotation?

What is the angle of rotational symmetry? What is the order or rotation?

What is the transformation image? What is the translation image?

General Outcomes:

• Students will describe the characteristics of 3D objects and 2D shapes, and analyze the relationships among them.
  • Students will demonstrate an understanding of similarity of polygons.
  • Students will draw and interpret scale diagrams of 2D shapes
• Students will also describe and analyze position and motion of objects and shapes.
  • Students will demonstrate an understanding or line rotation and symmetry.