Grade 8 Unit 2 Open Up Resources Vocabulary

center of a dilation

a fixed point on a plane. It is the starting point from which we measure distances in a dilation.

corresponding

When part of an original figure (points, segments, angles, or distances) matches up with part of a copy

dilation

a transformation in which each point on a figure moves along a line and changes its distance from a fixed point

similar

figures that have the same shape and angles; one can fit exactly over the other after rigid transformations and dilations

slope

a number we can calculate using any two points on the line using the dividing the vertical distance between the points by the horizontal distance.

Scale Factor

the ratio of the lengths of corresponding sides of similar figures which will stretch or shrink the image.

Stretch

to increase the dimensions of a figure proportionally when the scale factor is greater than 1.

Shrink

to decrease the dimensions of a figure proportionally when the scale factor is between 0 and 1.

Congruent

Figures that are identical in shape and size, meaning corresponding sides and angles are equal and their scale factor is 1.