Unit 3 Geometry Review (IM)

Front

What is the scale factor in a dilation?

Back

The scale factor is a number that describes how much a figure is enlarged or reduced during a dilation. It is the ratio of the lengths of corresponding sides of the image and the original figure.

Front

What does it mean for two figures to be similar?

Back

Two figures are similar if they have the same shape but not necessarily the same size. This means their corresponding angles are equal and their corresponding sides are proportional.

Front

How do you find the center of dilation?

Back

The center of dilation is a fixed point in the plane about which all points are expanded or contracted. It can be found by tracing the lines from corresponding points of the original and dilated figures.

Front

If a triangle has a perimeter of 24 and is dilated to a perimeter of 18, what is the scale factor?

Back

The scale factor is 3/4, calculated by dividing the perimeter of the image (18) by the perimeter of the original triangle (24).

Front

What is the relationship between the perimeters of similar figures?

Back

The ratio of the perimeters of two similar figures is equal to the scale factor of the dilation that maps one figure to the other.

Front

What is the perimeter of a triangle formed by connecting the midpoints of another triangle's sides?

Back

The perimeter of the triangle formed by connecting the midpoints is half the perimeter of the original triangle.

Front

What is a dilation in geometry?

Back

A dilation is a transformation that alters the size of a figure but not its shape, using a scale factor and a center of dilation.

Front

What is the formula for the scale factor when given the lengths of corresponding sides?

Back

Scale factor = Length of side in image / Length of corresponding side in original figure.

Front

What is the significance of congruent angles in determining similarity?

Back

If two figures have congruent corresponding angles, they are similar, as this is one of the criteria for similarity.

Front

How can you determine if two triangles are similar using side lengths?

Back

Two triangles are similar if their corresponding side lengths are in proportion, meaning the ratios of the lengths of corresponding sides are equal.