yego.me
💡 Stop wasting time. Read Youtube instead of watch. Download Chrome Extension

Non-congruent shapes & transformations


2m read
·Nov 10, 2024

  • [Instructor] We are told, Brenda was able to map circle M onto circle N using a translation and a dilation. This is circle M right over here. Here's the center of it. This is circle M, this circle right over here. It looks like at first, she translates it. The center goes from this point to this point here. After the translation, we have the circle right over here. Then she dilates it. The center of dilation looks like it is point N. She dilates it with some type of a scale factor in order to map it exactly onto N. That all seems right.

Brenda concluded, "I was able to map circle M onto circle N using a sequence of rigid transformations, so the figures are congruent." Is she correct? Pause this video and think about that. Let's work on this together. She was able to map circle M onto circle N using a sequence of transformations. She did a translation and then a dilation.

Those are all transformations, but they are not all rigid transformations. I'll put a question mark right over there. A translation is a rigid transformation. Remember, rigid transformations are ones that preserve distances, preserve angle measures, preserve lengths, while a dilation is not a rigid transformation.

As you can see very clearly, it is not preserving lengths. It is not, for example, preserving the radius of the circle. In order for two figures to be congruent, the mapping has to be only with rigid transformations. Because she used a dilation, in fact, you have to use a dilation if you wanna be able to map M onto N because they have different radii, then she's not correct. These are not congruent figures. She cannot make this conclusion.

More Articles

View All
When you’re pre-product market fit, sales is a job for the founders.
If you’re the founder of an early stage startup and you’re building a product that you’re hoping other businesses will buy, you are capable of selling it. That’s the good news. The bad news is that you’re probably the only person capable of selling your p…
Analyzing concavity (algebraic) | AP Calculus AB | Khan Academy
So I have the function G here; it’s expressed as a fourth degree polynomial. I want to think about the intervals over which G is either concave upwards or concave downwards. Let’s just remind ourselves what these things look like. Concave upwards is an i…
Water potential worked example
A zucchini squash was peeled and cut into six identical cubes. After being weighed, each cube was soaked in a different sucrose solution for 24 hours in an open container and at a constant temperature of 21 degrees Celsius. The cubes were then removed fro…
Cheap FPV Goggles for the NEO - DJI N3
Check out these goggles! They are the DJI N3, and they are a cheaper version of DJI’s FPV goggles. So that you could fly with the DJI Neo or the DJI Avada 2 and not have to spend $500 for a set of goggles. These are priced at $229. In this video, what I …
Bringing Life-Changing Treatments to the Blind in India | National Geographic
The world is invisible to the blind people, but at the same time, the blind people withdraw themselves from the surrounding, and they make them invisible. Unless the people who are cited actively try to find them out, they will remain in the dark. [Music…
Factoring polynomials using complex numbers | Khan Academy
We’re told that Ahmat tried to write ( x^4 + 5x^2 + 4 ) as a product of linear factors. This is his work, and then they tell us all the steps that he did, and then they say in what step did Ahmad make his first mistake. So pause this video and see if you …