Download Trigonometry and Angle Review ANGLES Angles are created by

Trigonometry and Angle Review
RIGHT ANGLE TRIANGLES
For right angle triangles the
trigonometric ratios are:
ANGLES
Angles are created by
rotating a ray from an
initial position to a
terminal position.
sinx =
opposite
hypotenuse
cosx =
adjacent
hypotenuse
tanx =
opposite
adjacent
We can use these ratios to find unknown side lengths, along
with the Pythagorean Theorem. (A2+O2=H2)
When the initial arm is on
the positive x-axis the angle
is in standard position.
Counterclockwise rotation
leads to positive angles,
clockwise rotation leads to
negative angles.
If given a vector, v, we can
determine the horizontal and
vertical components of that
vector, using the sine and
cosine functions, if we know
the direction and magnitude
of the vector.
Note that the quadrant that
the terminal arm is in will
affect the sign of the
components.
ACUTE AND OBTUSE TRIANGLES
OTHER ANGLE RELATIONSHIPS
Cosine Law:
The sum of the angles around a point is 360o.
Sine Law:
The sum of the angles in a triangle is 180o.
Supplementary Angles
Two angles are called supplementary angles if the sum of
their degree measurements equals 180 degrees.
∠ABC is the
supplement of
∠CBD
Complementary Angles
Two angles are called complementary angles if the sum of
their degree measurements equals 90 degrees.
∠ABC is the
complement
of ∠CBD
Matching angles - parallel lines cut by a transversal
PRACTICE - Find all of the missing side lengths and angles for
the triangles.
MORE HELP
Dave. Frequently Asked Questions About Trigonometry.
Accessed September 14, 2009. <http://catcode.com/trig/>.
David L.Heiserman. Basic Trigonometry. Free-Ed.Net Web.
Accessed September 14, 2009. <http://www.waybuilder.
net/free-ed/Math/Trigonometry/trig02_SPK.asp>