Transcript Basic Right Triangle Trig lesson

Right Triangle
Trigonometry Ratios
12.1
Must label the sides
C
marked angle
across from the
Opposite –
A
From the
marked
angle…
B
Adjacent – next to
the marked angle
Right triangle trig ratios:
x is an acute angle

Sin x = length of opposite side = o
length of hypotenuse
h
 Cos x = length of adjacent side = a
length of hypotenuse
h
 Tan x = length of opposite side = o
length of adjacent side a
Remember it this way:
SOH
CAH
TOA
o
a
tan x 
cos x 
a
h
Find sinC
o
sin x 
h
C
adjacent
1st Mark the angle given
2nd Label the triangle, opposite,
adjacent, hypotenuse
3rd Use your trig ratios:
B
5
opposite
A
o
sin x 
h
so
5
sin C 
13
Try these:
T
6
A
8
10
Write your
answers as
fractions and
simplify to
decimals
C
1. Sin C =
4. Sin A =
2. Cos C =
5. Cos A =
3. Tan C =
6. Tan A =
Find sinA, cosA, tanA
C
Oh no – what is missing?
12
B
A
9
In-Class Work

p. 625 #7-9, on number 8
write your answers as both
fractions and decimals