1. Trigonometry
(Continued)

2. C A H
S O H
T O A

3. What we know already!
O means theta
Hyp
opp O
Adj

4. Find the missing length
Sin O = opposite
hypotenuse
Sin 30º = Y 15
= y
0.5 x 15 = Y
Y = 7.5 15 Y
30°

5. Finding angles when you know the lengths

6. What if we know the length and want to find the angle?
14cm
Tan O = opposite
adjacent
Tan O = 14 17
Tan O =
Angle O = inv tan
Angle O = 39.47º O
17cm

7. Using the inverse button on your calculator, work out the following angles=
6) Sin =
7) Tan =
2) Cos = =
8) Sin
= 0.8
3) Tan
9) Cos =
4) Cos =
5) Tan
= 0.5
10) Tan =

8. Please copy the diagrams and find the missing lengths5 X
12º 9 C
20º 28 E A
33º 60 Y
6.2 B 25 20
35º 12 D 8 AC BC
42º 1
30º 30 2 Y 25 6
40º
70º 3 50 7
23º
30º 4
6.5 8
45º
40º