Instructional Video3:30
CK-12 Foundation

Rotation Symmetry: Lesson

6th - 11th
Find ways to spin a figure without it looking like it was rotating. The segment of a large geometry playlist introduces the idea of rotational symmetry. Using presentation tools, the presenter demonstrates whether particular figures have...
Instructional Video4:46
CK-12 Foundation

Interior Angles in Convex Polygons: Lesson

7th - 11th
How are angles and sides related? Given several regular convex polygons, the video shows how to calculate the sum of their interior angles. The segment in a playlist on geometry shows how to find the measure of one angle if the polygon...
Instructional Video4:41
CK-12 Foundation

Composing Transformations: Lesson

7th - 11th
Double the transformations, double the fun! Using the knowledge of transformations, the video combines two transformations of figures on the coordinate plane. The segment of a geometry playlist, finds a single transformation that will...
Instructional Video2:57
CK-12 Foundation

Tessellations: Lesson

6th - 11th
Build a pattern by rotating a figure around one of its vertices. A segment of an extensive playlist on basic geometry introduces the concept of tessellations through regular tessellations. The video shows how to create tessellations and...
Instructional Video5:40
CK-12 Foundation

Transformation - Rotation: Lesson

7th - 11th Standards
Change places by pivoting the figure. The section of a geometry playlist introduces rotations by making the connection to rotational symmetry. The presentation provides formulas to use with the coordinates when rotating a figure around...
Instructional Video2:38
CK-12 Foundation

Reflection Symmetry: Lesson

4th - 10th Standards
Symmetry is a natural thing. The video introduces the concept of reflection symmetry using a smiley face and a pentagon. Using pictures from nature, the installment of an extensive geometry playlist determines whether the object has...
Instructional Video7:07
CK-12 Foundation

Composite Solids: Lesson

8th - 11th Standards
Combine the formulas to arrive at one volume. Using the formulas for different solids, the video introduces finding the volume of composite solids. The portion of an extensive playlist on geometry works a couple of problems, one with an...
Instructional Video2:52
CK-12 Foundation

Calculating Areas of Sectors and Segments: Lesson

9th - 11th Standards
Find a slice of pi. The presentation talks through the process of finding the area of sectors and segments of circles. While working examples, the installment of an extensive geometry playlist uses the process to show the formulas for...
Instructional Video3:13
CK-12 Foundation

Area and Perimeter of Triangles: Lesson

6th - 10th Standards
Go from a parallelogram to a triangle. A segment of an extensive playlist on basic geometry shows the derivation of the formula for the area of a triangle. The resource works examples that require finding a missing side or height to...
Instructional Video4:24
CK-12 Foundation

Spheres: Lesson

8th - 11th Standards
Unwrap the surface of a sphere. A section of an extensive geometry playlist introduces the formulas for finding the surface area and volume of a sphere. The video includes a clip of how the surface area formula is developed by unwrapping...
Instructional Video3:57
CK-12 Foundation

Pyramids: Lesson

6th - 12th Standards
Pyramids: they're not just in Egypt! The segment of a large geometry playlist introduces the formulas to find the volumes and surface areas of regular pyramids. Using the formulas, the presentation works several examples to ensure your...
Instructional Video5:45
CK-12 Foundation

Prisms: Lesson

6th - 10th Standards
Set the bases of a conversation on prisms. The segment of a playlist on geometry introduces prisms and their parts. After visualizing prisms, the video discusses how to find the surface area and volume of prisms.
Instructional Video3:59
CK-12 Foundation

Three Dimensions in Two Dimensions: Lesson

6th - 11th Standards
Slice up solids. A portion of a geometry playlist introduces two conventional ways to visualize 3-D figures in 2-D. The resource defines cross-sections and nets and provides examples of both.
Instructional Video1:55
CK-12 Foundation

Calculating Area of a Circle: Lesson

6th - 11th Standards
It really is as easy as pi. The segment of a massive geometry playlist points out that the formula for the area of a circle is a relatively simple one. Using the formula, the presenter shows examples of finding the area of circles.
Instructional Video3:14
CK-12 Foundation

Circumference: Lesson

6th - 10th Standards
It all depends what is given. The section of a large geometry playlist discusses the two formulas for finding the circumference of a circle. With the aid of the formulas, the presenter demonstrates finding the distance around circles in...
Instructional Video4:21
CK-12 Foundation

Area and Perimeter of Rhombuses and Kites: Lesson

6th - 10th Standards
Flip the triangles up and create a parallelogram. Using the idea of transformations, the video develops the area formula for rhombi and kites. The segment of an extensive geometry playlist uses the formula to find the areas of different...
Instructional Video4:23
CK-12 Foundation

Area and Perimeter of Trapezoids: Lesson

6th - 11th Standards
With a little averaging, a trapezoid becomes a parallelogram. The section of an extensive geometry playlist shows how to derive the formula for the area of a trapezoid by changing it into a parallelogram. Using the formula, the video...
Instructional Video3:17
CK-12 Foundation

Graphing Circles: Lesson

9th - 11th Standards
Explore a standard method to graph a circle. Given the standard form of the equation of a circle, the segment of a basic geometry playlist shows how to graph the circle. The resource works examples of graphing a circle, finding the...
Instructional Video3:21
CK-12 Foundation

Area and Perimeter of Rectangles: Lesson

4th - 9th Standards
Around and in—take a different look at rectangles. A portion of a basic geometry playlist discusses the area and perimeters of rectangles. Using the formulas, the presentation works perimeter and area examples with rectangles and squares.
Instructional Video2:33
CK-12 Foundation

Segments from Secants: Lesson

9th - 11th
How are segments and secants related? A portion of an extensive geometry playlist demonstrates the relationship between the lengths of two secant segments from the same point. Using the relationship, the presenter works a few examples...
Instructional Video2:54
CK-12 Foundation

Segments from Chords: Lesson

9th - 11th Standards
Strike a chord length. The section of a larger playlist on geometry introduces the relationship relating lengths of intersecting chords. Using the relationship, the video shows how to find lengths of segments of the chords.
Instructional Video2:33
CK-12 Foundation

Angles Outside a Circle: Lesson

6th - 12th Standards
Understand the difference in finding angle measures. A segment of an extensive geometry playlist introduces the formula to find the measure of an angle formed outside of a circle. Using examples, the video shows how to calculate measures...
Instructional Video5:55
CK-12 Foundation

Inscribed Angles in Circles: Lesson

9th - 12th Standards
Circle the angles and intercept the arcs. The video introduces three theorems relating to inscribed angles in circles. Using drawings, the segment of a playlist on geometry illustrates the measure of angle along with theorems about two...
Instructional Video3:31
CK-12 Foundation

Transformation - Reflection: Lesson

7th - 11th Standards
Looking into a mirror is not the same on a coordinate plane. A portion of an extensive playlist on basic geometry provides the rules to find the coordinates of points after a reflection over one of the axis. Using the rules, the video...