Wednesday, April 2nd

1. Find the height of the parallelogram

2. 5 7

Find the missing side length

WARM UP8 m.

15 m.

h30°

EOCT Week 12 #3

RIGHT TRIANGLE QUIZ

Friday April 4th

Rest of the weekToday: Introduce trig ratios

Thursday: Finding missing side lengths using trig and Review

Friday: Quiz

5520 m

x

1.What is different about this triangle than yesterday’s triangles?

2.What is the same? 3.How could we find x?

Trig Ratios

The Trigonometric Functions

SINECOSINE

TANGENT

SINE

Pronounced “sign”

Pronounced “co-sign”

COSINE

Pronounced “tan-gent”

TANGENT

Prounounced “theta”

Greek Letter q

Represents an unknown angle

q

oppositehypotenuse

Sin OppHyp

Leg

adjacent

Cos AdjHyp

Leg

Tan OppAdj

Leg Leg

hypotenuse

opposite

adjacent

Trick to remember

SOHCAH TOA

Find the sine, the cosine, and the tangent of angle A.

Give a fraction.

hypoppAsin

8.109

hypadjAcos

8.106

adjoppAtan

69

32

9

6

10.8

A

Shrink yourself down and stand where the angle is.Now, figure out your

ratios.

Write the trigonometric ratio as a fraction and as a decimal rounded

to the nearest hundredth.Find sin J

Example 1

cos J

Write the trigonometric ratio as a fraction and as a decimal rounded to the nearest hundredth.

Example 2

tan K

Write the trigonometric ratio as a fraction and as a decimal rounded to the nearest hundredth.

Example 3

Find Sin A

Find Tangent B

Find Cosine A

Finding an angle.(Figuring out which ratio to use and an inverse trig button.)

111 tancossin

Ex: 1 Figure out which ratio to use. Find x. Round to the nearest tenth.

20 m

40 m

20tan40

q

26.6oq

1 20tan40

x

Tan-1 20 / 40 )

Shrink yourself down and stand where the angle is.

Now, figure out which trig ratio you have and set up the problem.

x

Ex: 2 Figure out which ratio to use. Find x. Round to the nearest tenth.

15 m50 m 15sin

50q

17.5 oq

1 15sin50

x

Sin-1 15 / 50 )

Shrink yourself down and stand where the angle is.

Now, figure out which trig ratio you have and set up the problem.

x

Ex. 3: Find q. Round to the nearest degree.

9

17.29

2.17tan q

q

62q

1 17.2tan 9 q

Ex. 4: Find q. Round to the nearest degree.

23

7

237cos qq

72q

1 7cos 23 q

Ex. 5: Find q. Round to the nearest degree.

400

200

400200sin q

q

30q

1 200sin 400 q

When we are trying to find a side we use sin, cos, or tan.

When we are trying to find an angle we use

(INVERSE) sin-1, cos-1, or tan-1.