4.1 Congruence

Front

What does it mean for two triangles to be congruent?

Back

Two triangles are congruent if they have the same size and shape, which means their corresponding sides and angles are equal.

Front

What is a rigid motion in geometry?

Back

A rigid motion is a transformation that preserves distance and angle measures, meaning the shape and size of the figure remain unchanged.

Front

What are the three types of rigid motions?

Back

The three types of rigid motions are translations, rotations, and reflections.

Front

How do you reflect a shape across the x-axis?

Back

To reflect a shape across the x-axis, you change the sign of the y-coordinates of each point of the shape.

Front

What is the effect of translating a shape 5 units to the right?

Back

Translating a shape 5 units to the right means adding 5 to the x-coordinate of each point of the shape.

Front

What is the notation for a 90-degree rotation about a point O?

Back

The notation for a 90-degree rotation about a point O is r(90°, O).

Front

What is the significance of congruence in geometry?

Back

Congruence is significant in geometry because it allows us to determine that two shapes are identical in form, which is essential for solving problems involving shape properties.

Front

What is the relationship between corresponding parts of congruent triangles?

Back

In congruent triangles, corresponding parts (sides and angles) are equal.

Front

What is the purpose of using transformations to prove congruence?

Back

Using transformations to prove congruence helps to visually demonstrate that two shapes can be made to coincide, confirming their congruence.

Front

What is a translation in geometry?

Back

A translation is a type of rigid motion that slides a shape in a straight line from one position to another without rotating or flipping it.