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 if two shapes are similar?

  All of the angles inside each shape
• What does it mean if two shapes have the same angles?

  It confirms that the shapes are similar
• What is typically asked in exams regarding similar shapes?

  To find an unknown side length
• What is the key to solving problems involving similar shapes?

  Finding the scale factor between the shapes
• How do you find the scale factor between two similar shapes?

  By comparing two equivalent sides
• If the larger shape's side is 6 cm and the smaller is 3 cm, what is the scale factor?

  2
• If the scale factor is 2, what is the length of a side measuring 5 cm on the smaller shape?

  10 cm
• What does "mathematically similar" mean?

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

  By dividing 12 cm by 8 cm
• What is the scale factor if 12 cm is divided by 8 cm?

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

  Multiply 26 cm by 1.5
• What is the length of y if its equivalent side is 45 cm and the scale factor is 1.5?

  30 cm
• When should you divide by the scale factor?

  When going from a larger shape to a smaller shape
• Why is it easier to find the scale factor from the smaller shape to the larger shape?

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

  $\frac{2}{3}$
• Why is it confusing to work with a scale factor less than one?

  It's harder to multiply and divide
• What is the process for finding missing sides in similar shapes?

  1. Identify the scale factor.
  2. Use equivalent sides to calculate unknown lengths.
  3. Multiply or divide based on shape size.
• What are the key concepts related to similar shapes?

  • Same shape, different sizes
  • Same angles confirm similarity
  • Scale factor determines side lengths
• Scale factor

  A ratio that represents the proportion of the original to the similar figure.
• Equivalent side

  A side of the similar figure that has the same measurement as the corresponding side of the original figure.
• Length of y given scale factor and equivalent side

  multiply the equivalent side by the scale factor