Curated Video
Classifying Triangles
Classifying Triangles explores the six types of triangles by defining the triangle types and classifying triangles by side length and angle measurement.
Curated Video
Subtract Angles
The video “Subtract Angles” reviews types of angles and demonstrates how to find unknown angle measures by using a subtraction equation with a symbol for the unknown angle measure.
Curated Video
Using Angle Measurement to Design a Graphic Logo
In this video, Kathy uses her knowledge of angles to design a graphic logo for her skateboard. She decomposes the design into congruent triangles and attempts to copy and paste them, but struggles to align them perfectly. Through trial...
Brian McLogan
Given the Value of Cotangent on the Unit Circle Find the Angle Measurement
👉 Learn how to evaluate the inverse of reciprocal trigonometric functions. Recall that the reciprocal trigonometric functions are given by the ratio of 1 and the corresponding trigonometric function. When an angle is unknown but the...
Brian McLogan
What are complementary and supplementary angles
👉 Learn about angles in trigonometry. An angle is the figure formed by two rays sharing the same endpoint. The two rays are called the sides of the angle while the common endpoint of the two rays is called the vertex of the angle. Angle...
Khan Academy
SAT Prep: Test 6 Section 9 Part 1
Word problems on the SAT can be some of the trickier questions. In this practice session from page 743 in The Official SAT Study Guide, Sal demonstrates how to read word problems as algebraic expressions, writing the necessary equation...
Khan Academy
SAT Prep: Test 5 Section 7 Part 5
Geometry problems on the SAT are often the most difficult for students to solve, let alone master. Focusing on several geometry-related skills (as well a few algebra problems), Sal makes this lesson a valuable resource for viewers who...
Khan Academy
SAT Prep: Test 5 Section 7 Part 2
Sal teaches the importance of careful reading and canceling out all possible units as he solves problems 6-9 on the practice SAT. Students who have a hard time deciphering word problems would benefit from this video. Sal's annotation and...
Flipped Math
Secants and Tangents
Put the vertex in, put the vertex out. Pupils explore theorems about the relationships of lengths of segments and angles of line segments that intersect inside or outside the circle. Learners use the theorems to solve problems involving...
Flipped Math
Addition Postulate
Add a little algebra to the geometry. Class members learn about the Addition Postulate for segments and angles. The pupils use their knowledge of solving equations to find lengths of segments and measures of angles. Individuals apply...
Flipped Math
Unit 1 Review: Tools for Geometry
Pupils review the vocabulary, formulas, and postulates from the opening unit in Geometry. Individuals use these to solve a problem set that requires learners to apply algebraic skills along with providing reasons within a proof. Scholars...
Flipped Math
Measuring Angles
An informative presentation shows pupils how to name and measure angles. Scholars revisit the different types of angles and their definitions and use their knowledge of what an angle bisector is to solve algebraic problems. At the end,...
Flipped Math
Intro to Trigonometry
Expand trigonometric ratios beyond right triangles. Pupils start with a review of trigonometric ratios and then take a look at angles in standard position to determine their measurements. Scholars discover how to find coterminal angles...
CK-12 Foundation
Interior Angles in Convex Polygons: Lesson
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...
CK-12 Foundation
Inscribed Angles in Circles: Lesson
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...
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
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
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
Corresponding Angles: Lesson
Take a parallel view of correspondence. The resource, part of a playlist on basic geometry, introduces the corresponding angle postulate. By first identifying corresponding angles, the video highlights the relationship between the angle...
CK-12 Foundation
Vertical Angles: Lesson
Define angles across from each other. An informative segment from a larger playlist on geometry introduces vertical angles and shows they have equal measures. Using their properties, the presenter solves problems involving vertical angles.
CK-12 Foundation
Supplementary Angles: Lesson
Supplement your knowledge of angles. Part of a playlist exploring geometry concepts, an interesting video introduces the definition of supplementary angles. Using the definition, the presentation shows how to find the supplement to a...
CK-12 Foundation
Complementary Angles: Lesson
Complement the angle definition. The resource, a video within a basic geometry playlist, introduces the definition of complementary angles. Using the definition, the presentation finds complements of given angles.
CK-12 Foundation
Measuring Angles: Lesson
Develop a degree of measurement. With the aid of a protractor, the video shows how to measure angles. The segment of a larger playlist on geometry basics points out that it is possible to start at a value other than zero when measuring...
Math Antics
Angles and Degrees
How do you determine the size of an angle? Pupils learn about degrees and how to measure the size of an angle. The video associates the measurements to types of angles such as acute, obtuse, and right. The additive properties of angle...