triangle angle sum 27 videos
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Angle of Elevation and Depression
Trigonometry Basic Trigonometry
How to define an angle of elevation or an angle of depression.
trigonometry angle of elevation angle of depression -
The Double-Angle Formulas
Trigonometry Advanced Trigonometry
How to use the sine and cosine addition formulas to prove the double-angle formulas.
the sine of a sum formula the cosine of a sum formula the sine double angle formula the cosine double angle formula -
Using Sine to Calculate the Area of a Triangle
Trigonometry Basic Trigonometry
How to calculate the area of any triangle using two sides and an included angle.
area of a triangle sine -
Radian Measure of Angles
Trigonometry Trigonometric Functions
How to measure angles using degrees or radians.
angle degree measure acute angle right angle obtuse angle radian measure -
Angle Inclination of a Line
Trigonometry Advanced Trigonometry
How to find the angle of inclination of a line.
angle inclination horizontal lines tangent slope -
30-60-90 Triangles
Trigonometry Pythagorean Theorem
How to find the legs and hypotenuse in 30-60-90 triangles when given: the short leg, the long leg, or the hypotenuse.
right triangle short leg long leg hypotenuse -
The Half-Angle Identities
Trigonometry Advanced Trigonometry
How to use the power reduction formulas to derive the half-angle formulas.
the power reduction formulas the half angle formulas quadrants -
45-45-90 Triangles
Trigonometry Pythagorean Theorem
How to find the length of a leg or hypotenuse in a 45-45-90 triangle using the Pythagorean Theorem.
isosceles right triangle leg hypotenuse Pythagorean theorem square root -
Other Forms of the Cosine Double-Angle Formula
Trigonometry Advanced Trigonometry
How to derive two more cosine double-angle formulas.
the Pythagorean identity the cosine double angle formulas -
The Sine Addition Formulas
Trigonometry Advanced Trigonometry
How to derive the sine of a sum formula.
cosine of a difference formula the cofunction identities the sine of a sum formula -
Inverse Trigonometric Functions
Trigonometry Basic Trigonometry
How to use inverse trig functions to find angles in right triangles.
trigonometry right triangle inverse sine cosine tangent -
Trigonometric Ratios: Sine
Trigonometry Basic Trigonometry
How to define the sine ratio and identify the sine of an angle in a right triangle.
trigonometry ratio right triangle sine SOH CAH TOA -
Trigonometric Ratios: Cosine
Trigonometry Basic Trigonometry
How to define the cosine ratio and identify the cosine of an angle in a right triangle.
trigonometry ratio right triangle sine SOH CAH TOA -
Trigonometric Ratios: Tangent
Trigonometry Basic Trigonometry
How to define the tangent ratio and identify the tangent of an angle in a right triangle.
trigonometry ratio right triangle sine SOH CAH TOA -
Evaluating Sine and Cosine at Other Special Angles
Trigonometry Trigonometric Functions
How to measure the sine and cosine of 150.
sine cosine unit circle definitions of sine and cosine angles in standard position reference angles -
Converse of the Pythagorean Theorem
Trigonometry Pythagorean Theorem
How to use the converse of the Pythagorean Theorem to determine if a triangle is a right triangle, how to use Pythagorean triples to memorize the lengths of certain right triangles.
right triangle leg hypotenuse converse Pythagorean triples -
The Tangent Function
Trigonometry Trigonometric Functions
How to define the tangent function for all angles.
tangent right triangle trigonometry the unit circle -
Evaluating Sine and Cosine at Special Acute Angles
Trigonometry Trigonometric Functions
How do we measure sine and cosine of pi/4?
sine cosine unit circle definitions of sine and cosine angles in standard position -
The Definitions of Sine and Cosine
Trigonometry Trigonometric Functions
How we define sine and cosine for all angle measures using the unit circle.
sine cosine right triangle definitions of sine and cosine angles in standard position unit circle definitions of sine and cosine -
Using the Pythagorean Theorem to find a Missing Hypotenuse
Trigonometry Pythagorean Theorem
How to calculate the hypotenuse in a right triangle given the lengths of the legs using the Pythagorean Theorem.
Pythagorean theorem leg hypotenuse right triangle