Download Section 4.6

Similarity and
Transformations
Section 4.6
Bellwork
Graph the polygon and its image after a dilation with scale factor k.
1. X(6, −1), Y(−2, −4), Z(1, 2); k = 3
2. A(0, 5), B(−10, −5), C(5, −5); k = 120%
Performing Similarity Transformations
A dilation is a transformation that preserves shape but not size. So, a
dilation is a nonrigid motion. A similarity transformation is a dilation
or a composition of rigid motions and dilations. Two geometric
figures are similar figures if and only if there is a similarity
transformation that maps one of the figures onto the other. Similar
figures have the same shape but not necessarily the same size.
Classifying Triangles by Sides and by Angles
Recall that a triangle is a polygon with three sides. You can classify
triangles by sides and by angles, as shown below.
Classifying Triangles by Sides and by Angles
Classify the triangular shape of the support beams in the diagram by its
sides and by measuring its angles.