This lesson teaches how to determine if two acute triangles are similar by examining their corresponding parts. It covers similarity transformations, including translation, reflection, rotation, and dilation, and explains how these transformations affect the shape and size of polygons. The lesson also discusses the properties of similar triangles, such as proportional sides and congruent angles. An example is provided to demonstrate how to verify triangle similarity using side lengths and angles, emphasizing the importance of proportionality and congruence in establishing similarity.

Which transformation changes the size of a polygon?

• Translation

• Reflection

• Rotation

• Dilation

What is a key property of similar triangles?

• They have the same size.

• Their corresponding angles are congruent.

• They have different shapes.

• Their corresponding sides are equal.

How can you confirm that two triangles are similar?

• By verifying that their corresponding sides are proportional.

• By checking if they have the same perimeter.

• By ensuring they have the same area.

• By checking if they are both right triangles.

What is the approximate ratio of the side lengths if side AT is 7.8 cm and side IG is 4.4 cm?

• 2.0

• 2.2

• 1.8

• 1.5

Why is it important to measure the sides of triangles when determining similarity?

• To ensure they have the same angles.

• To verify that the side lengths are proportional.

• To check if they are congruent.

• To determine their area.