This math video provides an introduction into triangles. It explains the classification of triangles based on their angle measure and the number of congruent sides. Examples include equilateral triangles, scalene triangles, isosceles, right, acute, and obtuse triangles. This video also contains practice problems on solving the angle measure of triangles.

Lines, Rays, Line Segments, & Angles:    • Lines, Rays, Line Segments, Points, A...  
Acute, Obtuse, Right, & Straight Angles:    • Acute Obtuse Right & Straight Angles ...  
Decimal Degrees to DMS Formula:    • Decimal Degrees to DMS Formula -  Con...  
Clock to Angle Problems:    • Clock Aptitude Reasoning Tricks & Pro...  
Angle Bisector Theorem - Midpoints:    • Angle Bisector Theorem - Midpoints & ...  
Converse, Inverse, & Contrapositive:    • Converse, Inverse, & Contrapositive -...  
Geometry Probability - Length & Area:    • Probability With Geometry - Length, A...  
Perpendicular Lines, Rays, & Segments:    • Perpendicular Lines, Slope, Rays, and...  
Complementary & Supplementary Angles:    • Complementary Angles and Supplementar...  
Addition & Subtraction Equality Property:    • Addition and Subtraction Property of ...  
Multiplication & Division Property Equality:    • Multiplication and Division Property ...  
Transitive Property of Congruence:    • Transitive Property of Congruence & S...  
Triangles - Basic Introduction:    • Triangles  
Alternate Interior & Exterior Angles:    • Parallel and Perpendicular Lines, Tra...  
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2 Column Proofs of Congruent Segments:    • Two Column Proofs of Congruent Segmen...  
2 Column Proofs of Angles:    • Geometry, Two Column Proofs of Angles...  
Triangle Congruence - SSS, SAS, ASA:    • Triangle Congruence Theorems, Two Col...  
CPCTC - 2 Column Proofs With Triangles:    • CPCTC Geometry Proofs Made Easy, Tria...  
Median of a Triangle Formula:    • Median of a Triangle Formula, Example...  
Altitude of a Triangle - Orthocenter:    • Altitude of a Triangle - Finding The ...  
Triangles, Medians, & Altitudes - Proofs:    • Two Column Proofs - Triangles, Median...  
2 Column Proofs - Isosceles Triangles:    • Geometry Proofs - Isosceles Triangles...  
Angle Side Theorem - 2 Column Proofs:    • Angle Side / Base-Angle Theorem - Two...  
Hypotenuse Leg Theorem - HL Postulate:    • Hypotenuse Leg Theorem - HL Postulate...  
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Detour Proofs - Double Triangle Congruence:    • Detour Proofs - Double Triangle Congr...  
The Midpoint Formula:    • Midpoint Formula  
Missing Diagrams - 2 Column Proofs:    • Missing Diagrams With Two Column Proofs  
Right Angle Theorem - SSS & SAS:    • Right Angle Theorem - SSS & AAS - Two...  
Perpendicular Bisector Theorem:    • Perpendicular Bisector of a Line Segm...  
Altitude, Median, Midpoint & P. Bisector:    • Altitudes, Medians, Midpoints, Angle ...  
Parallel & Perpendicular Lines - Slope:    • Finding The Slope Given Two Points - ...  
Indirect Proofs - Example Problems:    • Indirect Proofs, Practice Problems, T...  
Proving Parallel Lines With Proofs:    • Proving Parallel Lines With Two Colum...  
The Exterior Angle Theorem:    • Exterior Angle Theorem For Triangles,...  
Exterior Angle Inequality Theorem:    • Exterior Angle Inequality Theorem Wit...  
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Polygons:    • Polygons  
Quadrilaterals:    • Quadrilaterals - Geometry  
Parallelograms:    • Parallelograms - Geometry  
Rectangles - Special Quadrilaterals:    • Rectangles - Properties of Parallelog...  
Isosceles Trapezoids:    • Isosceles Trapezoids  
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Geometry Review - Study Guide:    • Geometry Introduction - Basic Overvie...  
Geometry Final Exam Review Questions:    • Geometry Final Exam Review - Study Guide