Similar Triangles: Ratios And Areas

• Similar triangles must have the same size.

  False
• What are corresponding angles in similar triangles called?

  Congruent
• What is the ratio of side AB in triangle ABC to side DE in triangle DEF if they are similar?

  $\frac{AB}{DE}$
• Steps to calculate unknown side lengths in similar triangles:

  1️⃣ Identify corresponding sides

  2️⃣ Set up the proportion

  3️⃣ Solve for the unknown
• What is the length of EF if AB = 6, DE = 12, and BC = 8?

  16
• What is the enlargement ratio if AB = 4 and DE = 8?

  2
• What is the ratio of the perimeters of similar triangles equal to?

  Enlargement ratio
• What is the area of triangle DEF if the area of triangle ABC is 20 square units and the enlargement ratio is 3?

  180
• If AB = 4, DE = 8, BC = 5, find EF.

  10
• Steps to solve problems involving similar triangles and ratios:

  1️⃣ Identify corresponding sides

  2️⃣ Set up proportions

  3️⃣ Solve for unknowns

  4️⃣ Check your answer