Defining Similarity
Site: | Saylor Academy |
Course: | GKT101: General Knowledge for Teachers – Math |
Book: | Defining Similarity |
Printed by: | Guest user |
Date: | Saturday, May 18, 2024, 3:22 AM |
Description
In this lecture, the transformations you have learned about previously are used to define similar shapes. Watch this video and complete the interactive exercises.
Similar shapes & transformations
Source: Khan Academy, https://www.khanacademy.org/math/geometry-home/similarity
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.
Practice
Similarity & transformations - Questions
1. Complete the similarity statement.
A rectangle is ________ (sometimes/always/never) similar to another rectangle, because we can ________ (sometimes/always/never) transformations.
2. Erin was able to map line segment onto line segment using a rotation and a dilation.
Erin concluded:
"I was able to map line segment onto line segment using a sequence of rigid transformations and dilations, so the figures are similar".
What error did Erin make in her conclusion?
(A) Erin used a dilation, so the segments aren't similar.
(B) The segments are congruent, not similar.
(C) There is no error. This is a correct conclusion.
3. Sabrina was able to map circle onto circle (with and being on each circle, respectively) using a translation and a dilation.
Sabrina concluded:
"I was able to map circle onto circle using a sequence of rigid transformations and a dilation, so the figures are similar".
What error did Sabrina make in her conclusion?
Choose 1 answer:
(A) Sabrina used a translation, so the circles aren't similar.
(B) Sabrina used a dilation, so the circles aren't similar.
(C) There is no error. This is a correct conclusion.
4. Konnor was curious if quadrilaterals and were similar, so he considered their angles.
Konnor concluded:
"The quadrilaterals have four pairs of congruent corresponding angles, so the figures are similar".
What error did Konnor make in his conclusion?
Choose 1 answer:
(A) The quadrilaterals are congruent, not similar.
(B) It's impossible to map onto using only rigid transformations and dilations, so the figures are not similar.
(C) There is no error. This is a correct conclusion.
Similarity & transformations - Answers
1. In conclusion, a rectangle is sometimes similar to another rectangle, because we can sometimes map one onto the other using only dilations and rigid transformations.
2. Erin concluded:
"I was able to map line segment onto line segment using a sequence of rigid transformations and dilations, so the figures are similar".
There is no error. This is a correct conclusion.
3. Sabrina concluded:
"I was able to map circle onto circle using a sequence of rigid transformations and a dilation, so the figures are similar".
There is no error. This is a correct conclusion.
4. Konnor concluded:
"The quadrilaterals have four pairs of congruent corresponding angles, so the figures are similar".
It's impossible to map onto using only rigid transformations and dilations, so the figures are not similar.