Lesson: Similarity of Polygons through Transformations Mathematics • 8th Grade

In this lesson, we will learn how to use a series of transformations to prove that two shapes are similar.

Lesson Plan

Students will be able to

prove similarity of two shapes on a grid using transformations,
identify which of the given shapes is similar to the original shape using transformations,
identify the corresponding points on two shapes, given that they are similar, using transformations,
identify the transformations that map one shape onto another similar shape,
draw a missing vertex for a shape given another shape similar to it.

Q1:

The figure shows two triangles: and .

Describe the single transformation that would map onto .

Hence, determine whether triangles and are similar.

Q2:

Triangle has been dilated from point to triangle and, hence, the two triangles must be similar.

What is the scale factor of the dilation?

Q3:

The triangle has been transformed onto triangle which has then been transformed onto triangle .

Describe the single transformation that maps onto .

Hence, are triangles and similar?