PBS
Human Tree: Dilations
Look at dilations exponentially. Using a fractal from a museum exhibit, the installment from the Math at the Core: Ratios series introduces the term dilation. The presenter points out that dilations can make images either smaller or...
Corbett Maths
Describing Reflections
Don't flip out over the resource, but be sure to flip the figures. By watching a short YouTube video, scholars learn about reflections in the coordinate plane. They see how to identify the line of reflection given two figures.
CK-12 Foundation
Congruent Triangles: Lesson
Given two congruent triangles, the resource provides the definition of congruent triangles and marks the corresponding parts. The portion of a basic geometry playlist shows the triangles are congruent by moving one on top of the other...
Khan Academy
Khan Academy: Geometry: Congruent Parts of Iscosceles Triangles
Proof that if the legs of an isosceles triangle are congruent then the base angles are congruent and vice versa using triangle congruency postulates. The proof is written as a two-column proof. [9:03]
Khan Academy
Khan Academy: Geometry: Congruent Triangle Example 2
Demonstrates how to use triangle congruency to prove that corresponding sides of congruent triangles are congruent and then identifies other congruent parts in the overlapping triangle diagram. The proof is written in the form of a...
Loyola University Chicago
Math Flix: Congruency
This QuickTime movie provides an opportunity to learn about the basic geometric term congruency. As you watch and listen to the teacher and student interact it helps clarify the thinking behind applying this concept.
Virtual Nerd
Virtual Nerd: What Does Congruent Mean?
Video tutorial explores the term congruent which is often used to describe figures that have the same size and shape. [5:21]
Sophia Learning
Sophia: Congruent Triangles: Lesson 3
This lesson will define the term congruent as it relates to triangles. It is 3 of 11 in the series titled "Congruent Triangles."
Khan Academy
Khan Academy: Introduction to Euclidean Geometry
In this video students gain an understanding of basic ideas in geometry and how we represent them with symbols.
Khan Academy
Khan Academy: Sss to Show a Radius Is Perpendicular to a Chord That It Bisects
More on the difference between a theorem and axiom. Proving a cool result using SSS.
Sophia Learning
Sophia: Notation for Congruent Parts
Explore the notation used to represent congruent sides and angles in a triangle. Take a quiz to assess learning.
Sophia Learning
Sophia: Regular Polygons Tutorial
In this video tutorial, students will determine if a polygon is regular by examining the sides and angles for congruency. Check understanding by the assessment. [2:06]
Virtual Nerd
Virtual Nerd: How Do You Identify Corresponding Parts in Congruent Triangles?
Follow along with this tutorial to understand how to identify corresponding sides and angles. [7:31]
Khan Academy
Khan Academy: Geometry: Proof: Opposite Sides of Parallelogram Congruent
Demonstrates how to prove that the opposite sides of a parallelogram are congruent based on knowledge of the special angles created when parallel lines are cut by a transversal and the triangle congruency postulates. [8:30]
Sophia Learning
Sophia: Corresponding Parts: Lesson 1
This lesson [2:00] will define the phrase corresponding parts (e.g. angles, sides, etc.). It is 1 of 5 in the series titled "Corresponding Parts."
Sophia Learning
Sophia: Double Diagonals of a Parallelogram: Lesson 1
This lesson cover the concept that that when both diagonals are drawn in on a parallelogram, two pairs of congruent triangles are formed. It is 1 of 5 in the series titled "Double Diagonals of a Parallelogram."
Sophia Learning
Sophia: Double Diagonals of a Parallelogram
This lesson cover the concept that that when both diagonals are drawn in on a parallelogram, two pairs of congruent triangles are formed.
Sophia Learning
Sophia: Corresponding Parts: Lesson 2
This lesson [4:27] will define the phrase corresponding parts (e.g. angles, sides, etc.). It is 2 of 5 in the series titled "Corresponding Parts."
Loyola University Chicago
Math Flix: Congruent Angles
This QuickTime movie provides an opportunity to learn about congruent/vertical angles. As you watch and listen to the teacher and student interact it helps clarify the thinking behind applying this concept.