New ReviewPuzzle your way through to a new understanding of area. Scholars learn about the area of polygons through equidecomposability, the idea that polygons that can be decomposed into the same set of pieces have the same area. By using...

Blow up a solid by a scale factor. A section of a larger playlist on basic geometry introduces the ratios of the surface areas and volumes of similar solids. Using the ratios, the video works several examples involving similar figures.

Explore relationships between similar rectangles with a unique approach. Scholars analyze data from imaginary balls on paper pool tables of different shapes to discover interesting patterns. They use ratios, factors, and multiples to...

Find the square of the scale factor. A component of a large playlist on geometry discusses the ratios of the perimeters and areas of two similar polygons. The resource shows examples in finding the ratios that lead to a pattern.

Judging by the sides, things appear similar. A portion of a larger playlist on geometry introduces the Side-Side-Side Similarity Theorem. The video shows how to use the lengths of sides to determine whether triangles are similar.

Develop an understanding of the scale of similarity. Starting with the concept of congruency, the resource introduces the idea of similarity between two figures. As part of a larger playlist on geometry, it defines similarity and uses...

The definition of similar to a mathematician is a little different than the average person. The first in a sequence of four lessons asks learners to investigates the criteria for similar figures. They compare side lengths between similar...

Zoom in to reveal more of the same. The resource introduces the concept of self similarity. Using a simple example, the video—part of a larger playlist covering geometry concepts—illustrates the meaning of a self similarity figure.

Two sets of congruent angles leads to three. Using diagrams of two triangles, the presentation intuitively shows that if two sets of angles are congruent, the third set is too. The portion of a geometry playlist uses that information to...

When given two sides and an angle, make similar triangles. The video describes the SAS Similarity Theorem. Using the theorem, the segment of a larger geometry playlist determines whether two triangles are similar.

Just a sip will make things smaller. Using Alice’s Adventures in Wonderland as a hook, the lesson introduces the idea of similarity. Pupils use it to find the distances on a map by applying the scale factor and creating similar triangles.

How high and how far does it go? Young scholars learn to count slope by drawing congruent triangles. The activity highlights the difference between positive and negative slope.

Are two angles enough? Given two triangles, the class determines through the definition of similarity and transformations whether the two triangles are similar. Provided with pairs of triangles and measurements, small groups find out...

How do you measure a distance where the measurement tool will not reach? Pupils use the concept of similar triangles to perform indirect measurements. The lesson asks teachers to demonstrate the method and lead the class through a set of...

Examine similarity through a lens of transformations. A creative question asks learners to explain the properties of the angles and sides of similar figures. They must use the definition of transformations to build their explanations.

Similar or not? Scholars use a given diagram of two triangles on a coordinate plane to determine if the triangles are similar. They must use similarity transformations to prove their answers.

Just how similar are dilations to isometries? The lesson builds upon pupils' knowledge of transformations and introduces the concept of dilations to obtain similar figures. Learners find out how to dilate a figure without the coordinate...

Congruence, similarity, and alikeness are ways to describe relationships between figures. While congruence and similarity are common geometric terms, the writer coins the term alikeness to include one-dimensional stretch transformations....

Show similarity with a similar approach to congruence. The assessment provides learners with two figures on a coordinate plane. Pupils use the coordinates of the figures and similarity transformations to describe how to show the two...

Pupils use a parallelogram containing intersecting line segments to identify two similar triangles. They justify the similarity and use it to find a missing length.

Develop a proof of the general case. Pupils develop a proof using transformations to prove the general case that any two circles are similar. The assessment provides minimum information about the two circles.

Mean is an average, but what is the geometric mean of two line segments? Scholars prove that the altitude to the hypotenuse is the geometric mean of the two parts of the hypotenuse. But first, they must explain why the two triangles...

Why are two triangles with congruent angles similar? Class members provide the justifications or explanations of the steps of a proof of the AA Similarity Theorem. The proof uses transformations as a basis to proving the theorem.

Geometry to the rescue. By watching a video, scholars see how geometric concepts help explain derivative formulas: areas of rectangles and volumes of rectangular prisms for the Power Rule and similarity and trig ratios for the Sine Rule.