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**Chapter 7: Introduction to Trigonometry (44 videos)**

**7.1: Measurement of an Angle**

**Introduction to an Angle****Measuring an Angle in Sexagesimal System****Sexagesimal System into Decimal form & Vice Versa****Radian Measure of an Angle****Relationship Between Radians & Degrees**

**7.2: Sector of a Circle**

**Relationship of Radius-Central Angle-Arc Length****Problem 1: Relationship of Radius-Central Angle-Arc Length****Area of a Circular Sector****Problem 1: Area of a Circular Sector**

**7.3: Trigonometric Ratios**

**General Angles****Angle in Standard Position****Problem-Angle in Standard Position****The Quadrants & Quadrantal Angles****Problem 1-The Quadrants & Quadrantal Angles****Trigonometric Ratios & Their Reciprocals****Problem 1-Trigonometric Ratios & Their Reciprocals****Trigonometric ratios of 45 degree****Problem 1: Trigonometric ratios of 45 degree****Trigonometric ratios of 30 degree and 60 degree****Problem 1: Trigonometric ratios of 30 degree and 60 degree****Signs of Trigonometric Ratios in Different Quadrants****Problem-Signs of Trigonometric Ratios in Different Quadrant****Values of Remaining Trigonometric Ratios****Values of Trigonometric Ratios at Quadrantal Angle****Problem 1-Values of Trigonometric Ratios at Quadrantal Angle**

**7.4: Trigonometric Identities**

**Proof of Fundamental Trigonometric Identity****Problem 1: Proof of Fundamental Trigonometric Identity****More on Fundamental Trigonometric Identity****Problem 1: More on Fundamental Trigonometric Identity****Problem 2: More on Fundamental Trigonometric Identity****Problem 3: More on Fundamental Trigonometric Identity****Problem 4: More on Fundamental Trigonometric Identity**

**7.5: Angle of Elevation and Angle of Depression**

**Concept of Angle of Elevation & Depression****Problem 1: Concept of Angle of Elevation & Depression****When one Side & Angle of Elevation are Given****Problem 1: when one Side & Angle of Elevation are Given****Problem 2: when one Side & Angle of Elevation are Given****When One Side & Angle of Depression are Given****Problem 1: when One Side & Angle of Depression are Given****When Hypotenuse & Angle of Elevation are Given****Problem 1: when Hypotenuse & Angle of Elevation are Given****When Given Sides-Angle of Elevation-Depression****Problem 1: when Given Sides-Angle of Elevation-Depression****Problem 2: when Given Sides-Angle of Elevation-Depression**