Download Day IV 4.3 right triangle trig

Math Analysis
Day III.
Right Triangle Trigonometry (4.3)
10/4/11
Two thirds of Americans can't do fractions. The other half, just don't care. Author Unknown
sin 30 =
sin 60 =
Sine and cosine are _________________________________
What is tangent’s cofunction? ____________________________
Cofunctions of complementary angles are equal. (θ = acute )
sin(90 - θ) =
cos(90 - θ) =
tan(90 - θ) =
cot(90 - θ) =
sec(90 - θ) =
csc(90 - θ) =
II. Trigonometric Identities
Reciprocal Identities:
sin θ =
cos θ =
tan θ =
csc θ =
sec θ =
cot θ =
Quotient Identities:
tan θ =
cot θ =
Pythagorean Identities:
sin²θ + cos²θ =
tan²θ + 1 =
1 + cot²θ =
IV. Applications Involving Right Triangles
Standard 12.0 - Students use trigonometry to determine unknown sides or angles in right triangles.
_______________________________________
Finding all the unknown angles and sides.
Example 3 - Using trigonometry to solve a right triangle
Solve the triangle if A = 61° and b = 18.
Your Turn
Solve the triangle if B = 62°30’ and c = 30.
Example 4 - Using trigonometry to solve a right triangle
In order to estimate the width of the straight river, a surveyor determined the measurements. Find the
width of the river.
Your Turn
Specifications for a loading dock ramp require a rise of 1 foot for each 3 feet of horizontal length. If the
ramp has a rise of 5 ft, solve the triangle.