Demonstrative Geometry

Chapter 5: Demonstrative Geometry (92 videos)   (Practice Test)

5.1: Theorems on Lines and Polygons

1. Elements in proving a geometrical theorem

5.2: Methods of Proof  (Practice Test)

1. Problem 1: Analytical and Synthesis method to Prove theorem
2. Law of Aristotle
3. Problem 1: Reductio-Ad-Absurdum Method
4. If two lines intersect each other,than vertical angles are congruent

5.3: Triangle  (Practice Test)

1. Interior and exterior of triangle
2. Problem 1: Interior and exterior of triangle
3. Triangluar Region and Triangular Area
4. Interior and exterior angles of traingle
5. Problem 1: Interior and exterior angles of traingle
6. Included Angle and Included Side of Triangle
7. Problem 1: Included Angle and Included Side of Triangle

5.4: Kinds of Triangle

1. Kinds of Triangle
2. Problem 1: Kinds of Triangle

5.5: One-One Correspondence between Two Triangles and Other Polygons

1. Congruence of Other Polygons

5.6: Congruence of Triangles

1. Congruency of Triangles
2. Problem 1: Congruency of Triangles

5.7: Congruence of Other Polygons

1. Congruence of Other Polygons
2. Problem 1: Congruence of Polygons

5.8: Postulate 14-Side Angle Side Postulate (S.A.S Postulate)  (Practice Test)

1. Side Angle Side Postulate
2. Problem 1: side angle side postulate
3. An exterior angle of a traingle is greater in measure than either of
4. Problem 1:An exterior angle of a traingle is greater in measure than

5.9: Transversal, Interior and Exterior Angles

1. Transversal, Interior and Exterior Angles
2. Problem 1: Transversal, Interior and Exterior Angles

5.10: Alternate Interior Angles

1. Alternate and corresponding Angles
2. Problem 1: Alternate and corresponding Angles

5.11: Corresponding Angles

1. Alternate and corresponding Angles
2. Problem 1: Alternate and corresponding Angles

5.12: Parallel Lines

1. Parallel Lines
2. Problem 1: Parallel Lines

5.13: Postulate 15. Parallel Lines Postulate  (Practice Test)

1. Parallel Lines Postulate
2. Problem 1: Parallel Lines Postulate
3. If a transversal intersects two coplanar lines
4. If a transversal intersects two parallel lines
5. Problem 1: If a transversal intersects two parallel lines

5.14: Parallelogram

1. Kinds of Parallelogram
2. Problem 1: Kinds of Parallelogram

5.15: Trapezoid or Trapezium  (Practice Test)

1. Trapezoid and Trapezium
2. Problem 1: Trapezoid and Trapezium
3. Sum of three angles of triangle is 180 degree
4. Problem 1: Sum of three angles of triangle is 180 degree
5. Angle opposite to equal sides are equal in triangle
6. Problem 1: Angle opposite to equal sides are equal in triangle
7. Angle-Side-Angle Postulate-1
8. Problem 1: Angle-Side-Angle Postulate-1
9. Side-Side-Side Postulate-3
10. Problem 1: Side-Side-Side Postulate-3
11. Sides Facing Equal Angles are Equal in Triangle-2
12. Problem 1: Sides Facing Equal Angles are Equal in Triangle-2
13. Hypotenuse Side Postulate-4
14. Problem 1: Hypotenuse Side Postulate-4
15. Diagonals of Parallelogram Bisects Each Other-1
16. Problem 1: Diagonals of Parallelogram Bisects Each Other-1
17. Problem 2: Diagonals of Parallelogram Bisects Each Other-1
18. Parallelogram Opposite Sides - Congruent -Parallel-2
19. Mid point Theorem-3
20. Problem 2: Mid point Theorem-3
21. Problem 1: Mid point Theorem-3
22. All Medians of Triangle Trisect Each Other-4
23. Problem 1: All Medians of Triangle Trisect Each Other-4
24. Proportional Segment Theorem-5
25. Perpendicular Bisector Theorem-1
26. Converse of Perpendicular Bisector Theorem-2
27. Triangle Right Bisectors of Sides are Concurrent-3
28. Problem 1: Triangle Right Bisectors of Sides are Concurrent-3
29. Problem 2: Triangle Right Bisectors of Sides are Concurrent-3
30. Angle Bisector Theorem-4
31. Converse of Angle Bisector Theorem-5

5.16: Theorems on Inequalities  (Practice Test)

1. Longer Side Inequality Theorem-1
2. Converse of Longer Side Inequality Theorem-1a
3. Problem 1: Converse of Longer Side Inequality Theorem-1a
4. Problem 2: Converse of Longer Side Inequality Theorem-1a
5. Triangle Sum of Two Sides is Greater Than Third-2
6. Problem 2: Triangle Sum of Two Sides is Greater Than Third-3
7. Shortest Distance from Point to a Line-3
8. Problem 2: Shortest Distance from Point to a Line-3
9. Problem 1: Shortest Distance from Point to a Line-3

5.17: Similar Figures  (Practice Test)

1. Proportional Parts of Triangle by Side Splitter Theo-1
2. Converse of Proportional Parts of Triangle -2
3. Division of Opposite Side by Angle Bisector-3
4. Proportional Parts of Similar Triangle-4
5. Converse of Proportional parts of similar triangle

5.18: Pythagoras Theorem  (Practice Test)

1. Pythagoras Theorem-1
2. Problem 1: Pythagoras Theorem-1
3. Problem 2: Pythagoras Theorem-1
4. Converse of Pythagoras Theorem-2
5. Problem 1: Converse of Pythagoras Theorem-2
6. Problem-Proof of Pythagoras Theorem
7. Problem-More on Proof of Pythagoras Theorem 1
8. Problem-Two Special Right Angled Triangles
9. Problem-More on Two Special Right Angled Triangles