Properties of Angles and Dilation

This video tutorial explains the concept of dilation, focusing on how enlarging or reducing a figure affects its properties. It reviews key vocabulary such as congruent angles, parallel lines, and scale factors. The process of dilating a parallelogram is demonstrated, showing how the resulting image maintains proportional sides and congruent angles, making the figures similar. The video also tests for parallelism, confirming that it is preserved in the dilated image. Finally, it discusses the effects of reducing figures, emphasizing that while side lengths change, angle measures and parallelism remain constant.

What is the term for angles that have the same measure?

• Divergent angles

• Similar angles

• Congruent angles

• Parallel angles

What happens to a figure when a scale factor greater than 1 is applied?

• The figure is reduced

• The figure is distorted

• The figure is enlarged

• The figure remains the same

What is the mathematical term for creating a new version of a shape through enlargement or reduction?

• Rotation

• Dilation

• Transformation

• Translation

If AB is 2 inches and A'B' is 4 inches after dilation, what can be said about these segments?

• They are identical

• They are parallel

• They are proportional

• They are congruent

What does it mean when two shapes are similar?

• They are identical in every way

• They have the same shape but different sizes

• They have different sizes and shapes

• They have the same size but different shapes

How can you test if the angles of two shapes are congruent?

• By using a virtual ruler

• By using active angles

• By checking their parallelism

• By measuring their lengths

What is preserved in a figure after dilation?

• The length of sides

• The angle measures

• The area

• The perimeter

What does the parallelism test confirm about a dilated figure?

• The figure is congruent

• The figure is distorted

• The figure is identical

• Parallelism is preserved

What changes in a figure after a dilation?

• Angle measure

• Parallelism

• Length of sides

• Shape

What is the definition of dilation in geometry?

• A transformation that reflects a figure

• A transformation that translates a figure

• A transformation that reduces or enlarges a figure

• A transformation that rotates a figure