Ch. 9 Second Quiz Flashcards
Trigonometric Ratio
The ratio of lengths of two sides of a rt. triangle
Tangent
The ratio of an acute angle involving lengths of legs of a rt. triangle.
Tangent = opp. side/adj. side
Solving a tangent equation
Tangent * (known angle measurement) = opp./adj.
Solve for unknown side
Sine
opposite/hypotenuse
Cosine
adjacent/hypotenuse
Sine and Cosine cannot be more than…
1 or less than -1
Sine/Cosine of Complementary Angles
The sine of an angle equals the cosine of its complement.
Sin (given angle) = Cos (90° - given angle)
Ex. Sin 20° = Cos 70°
Angle of Elevation
An angle that is formed between the horizontal line and the line of sight facing upwards
Angle of Depression
An angle that is formed between the horizontal line and the line of sight facing downwards
What are inverses used to find in a right triangle?
Angles
Tan -1 (x) = m<A iff
Tan A = x
Sin -1 (y) = m<A iff
Sin A = y
Cos -1 (z) = m<A iff
Cos A = z
Law of Sines
Sin A/a = Sin B/b = Sin C/c
Law of Cosines
a² = b²+c² - 2bc * Cos A
b² = a²+c² - 2ac * Cos B
c² = a²+b² - 2ab * Cos C
Area of Triangles
1/2bc Sin A
1/2ac Sin B
1/2ab Sin C
An altitude dropped from the vertex to the base in an isoceles triangle…
Is perpendicular and bisects the base
When you have a side multiplied by part of the hypotenuse * part of the hypotenuse + x
Distribute the known part of the hypotenuse
