CK-12 Foundation
Altitudes: Examples
Find the location of altitudes—from any elevation! The video presents the definition of an altitude of a triangle. By drawing examples, the segment of a larger geometry playlist highlights the location of altitudes of various triangle...
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
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
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
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
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
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
Using Ratios: Lesson
How do ratios work in geometry? The video answers just this question in order to help your class master an important skill. Using the concept of ratios, this segment in an extensive geometry playlist applies ratio reasoning to...
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
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
Midsegment Theorem: Lesson
Use half the length to connect the midpoints. A section of a playlist on geometry introduces the concept of a midsegment of a triangle and how to find it. The video states the properties of the midsegment which make up the Midsegment...
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
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...
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
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
Distance Between Parallel Lines: Lesson
Rely on slope when counting won't do. Using horizontal and vertical parallel lines, the presentation shows scholars how to find the distance by counting. The video uses the relationship of the slopes of perpendicular lines to find two...
CK-12 Foundation
Finding the Distance Between Two Points: Lesson
Point out an application of Pythagoras. The segment of an essential playlist on geometry provides a quick review of the Pythagorean Theorem. Using a right triangle to show the positions of two points, the presenter calculates the...
CK-12 Foundation
Perpendicular Lines in the Coordinate Planes: Lesson
Get the slope right with two easy steps. By placing two perpendicular lines on the coordinate plane, the video determines the relationship of the slopes of the two line lines. The resource is a part of an informative and extensive...
CK-12 Foundation
Parallel Lines in the Coordinate Plane: Lesson
Discover the parallel structure of parallel lines. Provided with two parallel lines on a coordinate plane, the presenter shows that the rise and run, or slope, of the two lines are the same. The resource, which is a portion of a larger...
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...