Right triangle trigonometry
Never use the ___ angle as reference
90 degree
Area of a triangle (new formula)
K=1/2absinC (Units are U²)
SOHCAHTOA
SIN (Opposite/Hypotenuse) COS (Adjacent/Hypotenuse) TAN (Opposite/Adjacent)
cofunctions
Sine(A)=Cosine(B), Sine(B)=Cosine(A) - sinA + cosB = 90
If you don't have a degree(angles) use the....
and Key!!!
Upper case letters represent
angles
reference angle is marked with an
arc
opposite the reference angle is called
opposite
Lower case letters represent
sides
Law of Sines
sinA/a=sinB/b=sinC/c
reference angle
the acute angle formed by the terminal side of an angle in standard position and the x-axis
angle of depression
the angle between the line of sight and the horizontal when an observer looks downward
angle of elevation
the angle formed by a horizontal line and a line of sight to a point above
adjacent side
the side next to the angle of reference
Hypotenuse
the side of a right triangle opposite the right angle
when using Law of sines to find an angle make sure to....
use 2nd sine after you have cross multiplied
Angle Measures using trig
when finding an unknown angle press second and then tan,cos, or sin depending on what sides you have. After that in the parentheses write the sides dividing each other depending on what you used. (this is what it should look like on your paper.... Cosθ=adj/hyp)
theta
θ<---- a variable commonly used in trigonometry to represent an unknown angle