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This page provides a list of educational videos related to Parallel Lines and Triangles. You can also use this page to find sample questions, apps, worksheets, lessons , infographics and presentations related to Parallel Lines and Triangles.
Find missing angles of triangles
By Khan Academy
Sal combines what we know about isosceles triangles and parallel lines with the power of algebra to solve the angles of an isosceles triangle.
McGraw-Hill Math Tutoring | MathHelp.com
By MathHelp.com
This lesson covers the midsegment of triangle. Students learn the following theorems related to parallel lines. If 3 parallel lines form congruent segments along one transversal, then they form congruent segments along every transversal. If a line intersects the midpoint of one side a triangle and is parallel to another side of the triangle, then it intersects the midpoint of the third side of the triangle. If a segment joins the midpoints of two sides of a triangle, then the segment is (a) parallel to the third side of the triangle, and (b) half the length of the third side. Students are then asked to solve problems related to these theorems using Algebra.
Triangle Proportionality Theorem - YourTeacher.com - Math Help
By yourteachermathhelp
Skip ahead to :18 to see an example question that requires us to understand that parallel lines (one of which is inside a triangle) creates two similar triangles. Watch how this type of question is solved using ratios.
Proving the Sum of Measures of Angles in a Triangle are 180
By Khan Academy
This video gives us a walkthrough of the proof that the angle measures of the angles of a triangle add up to 180. This proof requires us to draw in a line on our own (specifically, one that is parallel to one side of the triangle, but it could be any side). Then we can treat the two non-parallel sides as transversals.
Angle bisector theorem proof | Special properties and parts of triangles | Geometry | Khan Academy
By Khan Academy
In this video, we'll quickly review the angle bisector theorem, and then we'll see how it's proven. We prove it by extending a parallel line to one of the triangle's legs. That tells us information about the interior angles!
Angles (part 3) | Angles and intersecting lines | Geometry | Khan Academy
By Khan Academy
This video uses an electronic black board with different colored pens. Angles formed with two parallel lines (defines parallel lines) and a transversal line (a line that crosses the two parallel lines). The video then goes into labeling the various angles, corresponding angles, opposite angles, alternate interior angles, alternate exterior angles, and supplementary angles. The last thing the video explains is that all the angles in a triangle add up to 180 degrees. It shows how to find the measurements of each of these angles. Good video for review of concepts and angle vocabulary. Good for middle school students.
Triangle Similarity - AA SSS SAS & AAA Postulates, Proving Similar Triangles, Two Column Proofs
By The Organic Chemistry Tutor
This geometry video tutorial provides a basic introduction into triangle similarity. it explains how to use two column proofs in order to prove if two triangles are similar using the mostly the AA postulates. Other triangle similarity postulates mentioned are the AAA, SSS, and SAS postulates. Theorems used in this video include the base angle theorem, theorems associated with parallel lines, alternate interior angle theorem, vertical angles, reflexive property, definition of an altitude, right angle congruence, and more. This geometry video contains plenty of examples and practice problems on triangle similarity.
Similar Triangles, Part 2 - Khan Academy
By Khan Academy
Video uses an electronic black board with different-colored pens. In this video. Mr. Khan discusses the measurement of alternate interior angles, corresponding angles and how they are similar. Triangles are drawn in two parallel lines and a transversal. Narrator shows how to figure out the length of the sides of the angles when three sides are known. Good quality video. Good for middle elementary and middle school students.
Similar Triangles, Part 2 - Khan Academy
By Khan Academy
Video uses an electronic black board with different-colored pens. In this video. Mr. Khan discusses the measurement of alternate interior angles, corresponding angles and how they are similar. Triangles are drawn in two parallel lines and a transversal. Narrator shows how to figure out the length of the sides of the angles when three sides are known. Good quality video. Good for middle elementary and middle school students.
Triangle angle example 1 | Angles and intersecting lines | Geometry | Khan Academy
By Khan Academy
Figuring out angles in a triangle. A little about exterior angles being the sum of the remote interior angles
Triangle angle example 1 | Angles and intersecting lines | Geometry | Khan Academy
By Khan Academy
Figuring out angles in a triangle. A little about exterior angles being the sum of the remote interior angles
Understand Quadrilaterals - Trapezoid, Rhombus, Parallelogram, Rectangle, Square, Kite - [13]
By Math and Science
Quality Math And Science Videos that feature step-by-step example problems!
Learn Regular Polygons, Rhombus, Triangle, Parallelogram, Pentagon, Hexagon, Square - [5-9-3]
By Math and Science
Quality Math And Science Videos that feature step-by-step example problems!
ALL OF GRADE 9 MATH IN 60 MINUTES!!! (exam review part 3)
By Lumos Learning
Here is a great exam review video reviewing all of the main concepts you would have learned in the MPM1D grade 9 academic math course. The video is divided in to 3 parts. This is part 3: Geometry. In this video you will review parallel line theorems, pythagorean theorem, and volume/surface area of three dimensional shapes.
