CK-12 Foundation
Congruent Angles and Bisectors: Lesson
How is congruence shown? Using angles, the resource introduces the congruence symbol and explains the meaning of being congruent. A segment of a larger playlist on basic geometry discusses bisection as a way to arrive at two congruent...
CK-12 Foundation
Exterior Angles in Convex Polygons: Lesson
Going around is the same no matter the number of sides. An installment in a geometry playlist explains exterior angles of a convex polygon. The video presents the formula to find the sum of the angles along with the formula for finding...
CK-12 Foundation
Angle Bisectors: Lesson
Apply bisectors and distances to angles. Using the definition of an angle bisector, a portion of a geometry playlist draws a diagram showing the angle bisector. The video details properties of an angle bisector and their converses....
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
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
Creating Congruence Statements: Lesson
Provide a large amount of information in a short statement. A segment of a playlist on basic geometry introduces the notation to denote congruence between two figures. The video shows how to read corresponding parts from a congruence...
CK-12 Foundation
Trapezoids: Lesson
Using the definition of a trapezoid, the segment within a large playlist on basic geometry explains other properties of trapezoids. The video introduces the special properties held by isosceles trapezoids.
CK-12 Foundation
Proving a Quadrilateral Is a Parallelogram: Lesson
If it has the properties of a parallelogram, it must be a parallelogram. A segment of a playlist on geometry presents the converses of the properties of a parallelogram. Given a quadrilateral with specific characteristics, the video...
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
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
The Third Angle Theorem: Lesson
If two sets of angles are equal, the third set is too. An informative portion of a playlist on geometry develops the Third Angle Theorem for triangles. Using the theorem, the presenter shows how to determine the measure of missing angles...
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
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
Trigonometry Word Problems: Lesson
Look up or down to find the answer. A segment of an extensive playlist on geometry introduces angle of depression and elevation to find indirect measurements. Using trigonometric ratios, the presentation finds missing sides and...
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
The Trigonometric Ratios: Lesson
SOH, what is this thing called trigonometric ratios? A section of an extensive playlist on geometry identifies the adjacent and opposite sides in relationship of an angle. Using the identified sides, the video defines the sine, cosine,...
CK-12 Foundation
Comparing Triangle Angles and Sides: Lesson
Use the opposite to organize angles or sides. The video provides the relationship of angle measures based on the lengths of sides in a triangle and its converse. Using two triangles, the segment of a larger playlist on geometry shows the...
CK-12 Foundation
Triangle Inequality Theorem: Lesson
Can any three lengths make a triangle? One of the videos in a playlist on basic geometry introduces the Triangle Inequality Theorem. Using three given lengths, the presentation illustrates the restrictions on lengths of any side of a...
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
HL Triangle Congruence: Lesson
Use the right congruence statement. The video introduces the Hypotenuse-Leg Theorem to prove two right triangles are congruent. Part of a geometry playlist shows that it does not matter which leg to use when proving congruence.
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
Classifying Quadrilaterals in the Coordinate Plane: Lesson
Coordinate the classification of quadrilaterals. Given the definitions of special quadrilaterals, a portion of a geometry playlist highlights ways to classify a quadrilateral. The video takes information from figures on a coordinate...