Maths - symmetry

• What can be used to establish the similarity of triangles?

  Angle properties
• Enlargement and reduction scale factors can be used to calculate corresponding missing lengths
• Match the process with the concept it involves:

  Working backwards ↔️ Area scale factor

  Similar shapes ↔️ Enlargement or reduction

  Congruent shapes ↔️ Identical copies
• Enlargement and reduction scale factors can be used to calculate area problems.

  True
• What does it mean for shapes to be congruent?

  Identical in every way
• Shapes are still mathematically similar if one is a mirror image of the other.

  True
• Shapes are mathematically similar if one is an enlargement or reduction of the other
• All rectangles are not similar because only corresponding angles are always equal
• What are the two conditions for similarity between shapes?

  Proportional sides and equal angles
• All rectangles have right-angled corners, so corresponding angles are always equal.

  True
• Match the type of scale factor with its description:

  Enlargement scale factor ↔️ Reduces a shape

  Reduction scale factor ↔️ Increases a shape
• Match the term with its definition:

  Corresponding angles ↔️ Angles between parallel lines

  Equiangular triangles ↔️ Triangles with equal angles
• What must be true about corresponding sides or angles to prove triangle similarity?

  One condition must be true
• Triangles with corresponding angles are called equiangular triangles.

  True
• In the proof that triangle AED is similar to triangle ABC, both triangles share equal angles
• What type of angles allow us to find corresponding angles in diagrams?

  F angles
• Where do corresponding angles occur?

  Between parallel lines
• The area scale factor is equal to the square of the length scale factor.

  True
• The volume scale factor is equal to the cube of the length scale factor
• The volume of a cuboid is calculated by multiplying its length, width, and height.

  True
• Steps to work backwards using area or volume scale factors:

  1️⃣ Identify the area or volume scale factor

  2️⃣ Calculate the length scale factor

  3️⃣ Use the length scale factor to find the missing length
• By what percentage is the volume of a packet increased if its dimensions are increased by 20%?

  72.8%
• Increasing the dimensions of a packet by 20% increases its volume by 20%.

  False