Similar Triangles and Scale Factors

This video tutorial covers the concept of similar triangles, reviewing criteria for establishing similarity, such as angle-angle congruence. It demonstrates how to use scale factors to find missing side lengths and provides a step-by-step guide for solving triangle similarity problems. The lesson concludes with an example problem and a homework assignment.

What is one of the criteria for two triangles to be similar?

• They must have two congruent angles.

• They must have the same perimeter.

• They must have three congruent sides.

• They must have the same area.

How does the presence of parallel lines affect the similarity of triangles?

• It has no effect on the triangles.

• It creates corresponding angles that are congruent.

• It ensures the triangles have the same area.

• It makes the triangles identical.

If the scale factor between two similar triangles is 4, and a side of the smaller triangle is 2, what is the corresponding side length in the larger triangle?

• 8

• 0.5

• 2

• 4

What is the first step in solving a problem involving similar triangles?

• Find the scale factor.

• Prove the triangles are similar.

• Calculate the area of the triangles.

• Identify the longest side.

When given a smaller side and a scale factor, how do you find the corresponding larger side?

• Divide the smaller side by the scale factor.

• Multiply the smaller side by the scale factor.

• Subtract the scale factor from the smaller side.

• Add the scale factor to the smaller side.

In the example problem, what was the scale factor used to find the length of side AC?

• 1.5

• 1.6

• 4

• 2

What is the result of dividing a larger side by a smaller side in similar triangles?

• The perimeter of the triangle.

• The scale factor.

• The hypotenuse of the triangle.

• The area of the triangle.

If a side of a larger triangle is 8.96 and the scale factor is 1.6, what is the corresponding side length in the smaller triangle?

• 10.56

• 7.36

• 5.6

• 8.96

What should you do if you want to find a smaller side from a larger side using the scale factor?

• Divide by the scale factor.

• Subtract the scale factor.

• Add the scale factor.

• Multiply by the scale factor.

What is the homework assignment related to this lesson?

• Read pages 50-55 and solve problems 1-3.

• Write an essay on triangle similarity.

• Solve problems 6-10 on page 62.

• Complete pages 59-61, problems 1-5.