Lumos Video Store
This page provides a list of educational videos related to Circles and Arcs. You can also use this page to find sample questions, apps, worksheets, lessons , infographics and presentations related to Circles and Arcs.
Basic information about circles
By MathPlanetVideos
What's the angle of the circle arc if we divide a cicle in 12 equally sized pieces
[4.MD.5a-2.0] Angle Measurement - Common Core Standard
By Freckle education
Understand that an angle is measured by considering the fraction of the circular arc between the points where the two rays intersect the circle
Inscribed Angles - YourTeacher.com - Geometry Help
By yourteachermathhelp
Students learn the definition of an inscribed angle, and that the measure of an inscribed angle is equal to ½ the measure of its intercepted arc. Students also learn the following theorems related to inscribed angles. If two inscribed angles intercept the same arc, then the angles are congruent. An angle inscribed in a semicircle is a right angle. If a quadrilateral is inscribed in a semicircle, then opposite angles are supplementary. The measure of an angle formed by a chord and its tangent is half the measure of the intercepted arc. Students are then asked to find the missing measures of arcs and angles in given circles using these theorems.
Radian and degree | Unit circle definition of trig functions | Trigonometry | Khan Academy
By Khan Academy
This video explains what a radian is and how we determine the radian measure of an angle. The key point here is that the radian measure of an angle is the length of the arc (in radius lengths) cut off by that angle (if the angle's vertex is on the center of the circle). You may ask: Won't the size of the circle affect the radian measure of an angle? A key feature of circles is that they are all similar (and thus, proportional). When we account for their larger size, we take into account the larger radius. As a result, the radian measure is the same for all circles (since the radian measure is how many radius lengths long the arc is).
11.6 Areas of Circles, Sectors & Segments (Lesson)
By AutenMath
A lesson on finding the area of circles, sectors and segments
Partitioning Circles and Rectangles: 2.G.3
By Tenmarks Amazon
Students learn to create and discuss halves, thirds, and fourths of circles and rectangles.
Partitioning Circles and Rectangles: 2.G.3
By Tenmarks Amazon
Students learn to create and discuss halves, thirds, and fourths of circles and rectangles.
Partitioning rectangles, squares, and circles into halves and fourths-2nd grade
By Tyris Hall
Partitioning rectangles into halves
Tangents and Circles - YourTeacher.com - Geometry Help
By yourteachermathhelp
Students learn the following theorems related to tangents. If a line is tangent to a circle, then the line is perpendicular to the radius at the point of tangency. If a line is perpendicular to a radius at its outer endpoint, then the line is tangent to the circle. If two tangent segments are drawn to a circle from an external point, then the tangent segments are congruent. Students are then asked to use these theorems to find missing segment lengths and missing angle measures in given figures. Students also learn the definitions of common internal tangents and common external tangents.
Area of inscribed equilateral triangle (some basic trig used) | Circles | Geometry | Khan Academy
By Khan Academy
This video will give you a good feel for what inscribed figures are like. It uses some trigonometry to figure out what the area of an equilateral triangle inscribed in a circle is, given the circle's radius. NOTE: We don't actually need trigonometry to solve this problem. Notice that we can view the equilateral triangle as six identical 30-60-90 triangles, the hypotenuses of which are radii of the circle, then use the 30-60-90 triangle side length ratios to figure out the rest of what we need to know to solve the problem.
Area of inscribed equilateral triangle (some basic trig used) | Circles | Geometry | Khan Academy
By Khan Academy
This video will give you a good feel for what inscribed figures are like. It uses some trigonometry to figure out what the area of an equilateral triangle inscribed in a circle is, given the circle's radius. NOTE: We don't actually need trigonometry to solve this problem. Notice that we can view the equilateral triangle as six identical 30-60-90 triangles, the hypotenuses of which are radii of the circle, then use the 30-60-90 triangle side length ratios to figure out the rest of what we need to know to solve the problem.
Math-U-See Geometry - Homeschooling Help Circles Inscribed Angles - TabletClass.com
By TabletClass Math
Youtube Presents Math-U-See Geometry - Homeschooling Help Circles Inscribed Angles - TabletClass.com an educational video resources on math
Inscribing and circumscribing circles on a triangle
By Khan Academy
Inscribing and circumscribing circles on a triangle
Circles: radius, diameter, circumference and Pi | Geometry | Khan Academy
By Khan Academy
The radius is the distance between the center and any point on the circumference of a circle. The diameter is always twice the radius. The circumference is the perimeter of the circle.
Equation for a circle using the Pythagorean Theorem | Circles | Geometry | Khan Academy
By Khan Academy
Equation for a circle using the Pythagorean Theorem | Circles | Geometry | Khan Academy
Proof: Right triangles inscribed in circles | High School Math | Khan Academy
By Khan Academy
Proof showing that a triangle inscribed in a circle having a diameter as one side is a right triangle. All Khan Academy content is available for free at www.khanacademy.org