CK-12 Foundation
Two-Column Proofs: Lesson
Why is it a two-column proof? A video introduces the class to the concept of a two-column proof and how to set one up. The segment of a playlist on basic geometry highlights the types of reasons that can be in a proof.
CK-12 Foundation
Indirect Proofs in Algebra and Geometry: Lesson
Indirectly, it is a good proof method. A segment of a playlist on geometry introduces a way to prove geometric and algebraic statements. Using a general examples, the video shows how to develop an indirect proof.
CK-12 Foundation
Conjectures and Counterexamples: Lesson
The first five are red, so they all must be red, right? As part of a larger playlist on basic geometry, the video walks through an example of a conjecture and counterexamples by using a scenario of pulling candy out of a bag.
CK-12 Foundation
Same Side Interior Angles: Lesson
Supplement your scholars' knowledge of angles involved with parallel lines. Using the properties of alternate interior angles and linear pairs, the presenter shows interior angles located on the same side of a transversal of parallel...
CK-12 Foundation
Alternate Exterior Angles: Lesson
Use an alternate approach to parallel lines. A resource in a comprehensive playlist on basic geometry develops the concept of alternate exterior angles and parallel lines. The presentation demonstrates how to identify alternate exterior...
CK-12 Foundation
Isosceles Triangles: Lesson
Two sides give us two angles. A segment of a playlist on basic geometry revisits isosceles triangles. The presentation explains several properties and theorems related to isosceles triangles.
CK-12 Foundation
Using the Pythagorean Theorem: Lesson
Is it right to use the converse? A segment of a basic geometry playlist introduces the Pythagorean Theorem and its converse. The video uses Pythagorean triples when finding whether a triangle is a right triangle or not.
CK-12 Foundation
Proportions with Angle Bisectors: Lesson
Half at one end becomes proportional on the other. As part of a basic geometry playlist, the video introduces the Angle Bisector Theorem. The presentation uses the theorem to find missing lengths in triangles.
CK-12 Foundation
Inscribed Similar Triangles: Lesson
Create similar triangles with a little altitude. A section of an extensive playlist on basic geometry discusses how an altitude of a right triangle creates similar triangles. Using the theorem, the presentation finds unknown side...
CK-12 Foundation
Classifying Parallelograms: Lesson
Properly organize parallelograms. Given special parallelograms, the narrator of a short video explains the properties of each. The section of a playlist on geometry uses the properties to classify the special parallelograms.
CK-12 Foundation
Triangle Sum Theorem: Lesson
The measures all add up. The presentation, part of a helpful playlist on geometry, provides the statement of the Triangle Sum Theorem. Using the theorem, the video shows how to find the missing measure of an angle.
CK-12 Foundation
Chords in Circles: Lesson
Strike a chord with four theorems. The segment of a playlist on geometry introduces four basic theorems about chords in a circle. Theorems include the relationships between diameters and chords, congruent chords and arcs, and congruent...
CK-12 Foundation
Alternate Interior Angles: Lesson
Concepts of alternate interior angles parallel the concepts of corresponding angles. Using a diagram, the presentation defines and identifies alternate interior angles formed by a transversal and two parallel lines. The video in a...
CK-12 Foundation
Exterior Angles Theorems: Lesson
Use the inside to find the outside. The resource presents two theorems dealing with exterior angles of a triangle. Using the two theorems, the segment from a larger geometry playlist works problems to solve for angle measures.
CK-12 Foundation
SAS Triangle Congruence: Lesson
SAS is not just a spy organization. A section of an extensive geometry playlist introduces a way to show two triangles are congruent, SAS. Using diagrams, the video provides an explanation by showing only one triangle is formed with two...
CK-12 Foundation
SAS Similarity Theorem: Lesson
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.
CK-12 Foundation
Equilateral Triangles: Lesson
Take a second look at triangles that are equal all the way around. The video reminds viewers what an equilateral triangle is and points out that the three angles are the same. Using the fact that equilateral triangles are also isosceles,...
CK-12 Foundation
ASA and AAS Triangle Congruence Lesson
The location of the side makes a difference. One of the videos in a geometry playlist introduces angle-side-angle and angle-angle-side congruence relationships. Using drawings, the video shows how these two congruence statements are...
CK-12 Foundation
SSS Triangle Congruence: Lesson
Gimme three sides, mister! The video introduces the Side-Side-Side Triangle Congruence Theorem. Using segments of different lengths, the portion of a larger playlist on geometry shows that only one triangle can be built.
CK-12 Foundation
Parallelograms: Lesson
Properties spawn from parallel sides. With the aid of diagrams, the presentation shows the different properties of parallelograms. The segment of an extensive geometry playlist lists the properties that using the parallel sides of a...
CK-12 Foundation
Triangle AA Similarity: Lesson
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...
CK-12 Foundation
Parallel Lines and Transversals: Lesson
Segment transversals proportionally. Given a diagram with three parallel lines and two transversals, the narrator of a short video points out the parallel lines cut the transversals proportionally. The portion of a long playlist on...
CK-12 Foundation
SSS Similarity Theorem: Lesson
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.
CK-12 Foundation
Inscribed Quadrilaterals in Circles: Lesson
Find supplementary information about inscribed angles. A section of a large geometry playlist introduces the relationship of angles in an inscribed quadrilateral. The presentation works through examples that use the relationship between...