Learn about the characteristics required for congruent or similar figures. This video focuses on the variety of ways you can use the side and angle measurements of two triangles to check for congruence and also briefly discusses how that differs from similar figures. This video was submitted through the Innovation Math Challenge, a contest open to professional and nonprofessional producers.
Watch an animated demonstration of translating and reflecting a triangle on the coordinate plane in this video from KCPT. In the accompanying classroom activity, students watch the video and then consider the effect of translating and reflecting on the coordinates of the vertices of the triangle. Next, they draw translations and reflections of a triangle and identify the number of units and direction of translation as well as the lines of reflection in classmates drawings. To get the most from the lesson, students should be comfortable graphing points on the coordinate plane. Prior exposure to reflection is helpful.
Learn about reflections through examples from landscape architecture in this video from MPT. In the accompanying classroom activity, students identify reflection lines in photographs of designed landscapes. Next, they draw a triangle and graph its reflections over the x-axis and y-axis. They then consider changes in coordinates that result from these reflections. To get the most from the lesson, students should be comfortable graphing in all four quadrants of the coordinate plane. For a longer self-paced student tutorial using this media, see "Transformations in Landscaping" on Thinkport from Maryland Public Television.
Watch as the National Museum of Mathematics uses an image of a visitor to create a "Human Tree" using dilations. This video focuses on how similar figures can create dilations and how exponents can be used in an equation to express the proportional relationship in fractals. This video was submitted through the Innovation Math Challenge, a contest open to professional and nonprofessional producers.
In this classroom resource from Desmos, students will explore what happens when they dilate a single point from a center through playing rounds of mini-golf. The students will move from informal to formal ways of determining the relationships between the center, the pre-image, the image, and the scale factor. This resource could be used to help teach a lesson on dilations. The resource includes sample student responses and a teacher guide.
In this Desmos activity, students will use their existing understanding of translations, reflections, and rotations to complete a round of transformation golf. For each challenge, their task is the same: use one or more transformations to transform the pre-image onto the image. This activity could be used to help teach a lesson on transformation. This Desmos activity offers sample student responses and a teacher guide.
In this Desmos activity, students will use their existing understanding of translations, reflections, rotations, and dilations to complete a round of transformation golf. For each challenge, their task is the same: use one or more transformations to transform the pre-image onto the image. This activity could be used to help teach a lesson on translations. This Desmos activity offers sample student responses and a teacher guide.
In this Desmos lesson, students are informally introduced to dilations through experimenting with "sketching machines" that allow them to adjust various parts of a drawing to see the effect on the pre-image. Students are then introduced to similarity as the result of dilation. This activity should be used to help teach a lesson on transformations. This Desmos activity offers sample student responses and a teacher guide.
