Outline
Grade -9 NCERT -Maths Made Easy
NCERT GRARDE 9
6. LINES AND ANGLES
7. TRIANGLES
8. QUADRILATERALS
9. AREAS OF PARALLELOGRAMS AND TRIANGLES
10. CIRCLES
13. SURFACE AREAS AND VOLUMES
Table of Contents
Writing Prompts: Definitions & Theorems
- Congruent Segments: Quick Exploration
- Congruent Angles: Definition
- Midpoint Definition
- Segment Bisector Definition
- Perpendicular Bisector Definition
- Perpendicular Bisector Definition
- Angle Bisector Definition (I)
- Complementary Meaning?
- Supplementary Angles (Quick Exploration)
- Triangle Altitude Illustrator and Definition Writing Prompt
- Triangle Median Illustrator & Definition Writing Prompt
- Equilateral Action!!!
- Equiangular Action!!!
- Regular Polygon Action!
Parallel Lines & Related Angles
- Vertical Angles Theorem
- Exploring Corresponding Angles (V2)
- Alternate Interior Angles Theorem (V1)
- Exploring Alternate Interior Angles (V2)
- Alternate Interior Angles Theorem (V3)
- Alternate Exterior Angles Theorem (V1)
- Exploring Alternate Exterior Angles (V2)
- Alternate Exterior Angles Theorem (V3)
- Same Side Interior Angles Theorem
- Exploring Same Side Exterior Angles
- Solution to Parallel Lines & Angles Problem
Polygons & Angles: Interior & Exterior Angles
Quadrilaterals: Theorems & Properties
- Parallelogram: Theorem 1
- Parallelogram: Theorem 2
- Parallelogram: Theorem (3)
- Parallelograms (I)
- Parallelogram Diagonals
- Quad Midpoints Action!
- Rhombus Action!
- Rhombus Diagonals
- Rectangle Action!
- Rectangle Diagonals
- Square Action!
- Isosceles Trapezoid Action!
- Trapezoid Median: 2 Discoveries
- Isosceles Trapezoid Diagonals
- Isosceles Trapezoid Midpoints
- Kite Action!
Triangles: Theorems & Properties
- SAS: Dynamic Proof!
- SSS: Dynamic Proof!
- SSS: Dynamically Illustrated
- ASA Theorem?
- Similar Right Triangles (V1)
- Similar Right Triangles (V2)
- AA Similarity Theorem
- SAS ~ Theorem
- SSS ~ Theorem (V1)
- SSS ~ Theorem (V2)
- Parallel Lines Proportionality Theorem
- Triangle-Angle Bisector Theorem
- A Special Triangle & Its Properties (I)
- Converse of IST (V1)
- Isosceles Triangle Medians
- Triangle Midsegment Action!
- Triangle Midsegment
- Another Special Triangle and its Properties (II)
- Converse of IST (II)
- Incenter & Incircle Action!
- Incenter + Incircle Action (V2)!
- Medians and Centroid Dance
- Circumcenter & Circumcircle Action!
- Midpoint of HYP
- 3 Special Points!
Circle Theorems
- Congruent Circles: Definition
- Properties of Tangents Drawn to Circles (A)
- Properties of Tangents Drawn to Circles (B)
- Diameters & Chords I (VA)
- Diameters & Chords I (VB)
- Congruent Chords (I)
- Inscribed Angle Theorem (V1)
- Inscribed Angle Theorem Dance: Take 2!
- Inscribed Angle Theorem: Corollary 1
- Thales' Theorem (VA)
- Cyclic Quadrilaterals (IAT: Corollary 3)
- Cyclic Quadrilateral: Proof Hint
- Cyclic Quadrilateral: Quick Warm Up (GoGeometry Action 149!)
- Angle Formed by Chord & Tangent (I)
- Crossing Chords: Proof Hint
- Congruent Chords Action (A)
- Equidistant Chord Action
- Butterfly Theorem Action!
Geometric Constructions
Transformations
Area, Surface Area, Volume