Similarity

• What are similar shapes?

  Shapes with the same shape but different sizes
• How can you tell if two shapes are similar?

  By checking if they have the same angles
• What do you need to find to determine the scale factor between two similar shapes?

  Compare two equivalent sides of the shapes
• What does a scale factor of two indicate about the shapes?

  Every length on the larger shape is twice as long
• If the smaller shape has a side of 5 cm, what is the corresponding side in the larger shape with a scale factor of 2?

  10 cm
• What does the term "mathematically similar" mean?

  It means similar shapes as discussed
• How do you find the scale factor between two triangles with sides of 8 cm and 12 cm?

  Divide 12 cm by 8 cm
• What is the scale factor if the larger triangle side is 12 cm and the smaller is 8 cm?

  1. 5
• How do you find the length of side x if the equivalent side is 26 cm and the scale factor is 1.5?

  Multiply 26 cm by 1.5
• If the equivalent side for y is 45 cm and the scale factor is 1.5, how do you find y?

  Divide 45 cm by 1.5
• Why is it important to determine whether to multiply or divide by the scale factor?

  To ensure you get the correct side length
• What is the advantage of finding the scale factor from the smaller shape to the larger shape?

  It avoids confusion with fractions less than one
• What is the scale factor from shape d to shape c if the sides are 8 cm and 12 cm?

  Two-thirds
• Why is it harder to work with a scale factor less than one?

  It's harder to multiply and divide by small numbers
• What are the steps to find a missing side in similar shapes?

  1. Identify the scale factor.
  2. Use equivalent sides for calculations.
  3. Multiply or divide based on shape size.
• What is the relationship between angles in similar shapes?

  • All corresponding angles are equal.
  • This confirms the shapes are similar.
• What should you remember when calculating scale factors?

  • Always find from smaller to larger shape.
  • Avoid fractions less than one for simplicity.