1. “Triangle Measurement”
TRIGONOMETRY
“Triangle Measurement”

2. The Triangle B c a C A b Angles : Capital Letters
Sides: Lower Case Letters c a C A b

3. The Triangle Hypotenuse Opposite Adjacent A Opposite:Across From
Adjacent:Part of A
Adjacent
Hypotenuse:Across
From the Right Angle

4. SOHCAHTOA
hypotenuse
opposite A

5. SOHCAHTOA
hypotenuse A
adjacent

6. SOHCAHTOA
Opposite A
Adjacent

7. Labeling Triangles Adjacent Opposite Hypotenuse b a A c B
Label the triangle according to angle A. Label the opposite side, adjacent
side and the hypotenuse. Then name Angle B, side a, b, and c.
Adjacent b
Opposite a A c
Hypotenuse B

8. Calculator Practice Determining trig values… Sin 52° = Cos 62° =
Given the angle measure, use the sine (sin), cosine (cos) and tangent (tan) buttons, determine the trig values of each. Round to 4 decimal places.
Sin 52° =
Cos 62° =
Tan 25° =
.7880
.4695
.4663

9. Calculator Practice Determining Angle Measures… Sin .9877 =
Given the trig values, use the inverse function to determine the angle measures. Round to the nearest degree.
Sin =
Cos =
Tan =
81º
11º
40º

10. Solving Triangles
Solving triangles means to find all of the angles and
all of the sides.
Given the following triangle, find the missing side, set up the ratios, and find the missing angles.
x =
Sin A =
Cos A =
Tan A =
Angle A =
Angle B = 6
82 + x2 = 102
8/10
64 + x2 = 100
8 cm
x2 =
6/10
10 cm
x2 = 36
8/6
x = 6
53° A =
37°
x cm

11. Mnemonics "Tommy On A Ship Of His Caught A Herring" (probably more
common in Great Britain than the United States).
2. "Oscar Has A Hold On Angie.”
3. "Oscar Had A Heap of Apples.”
"The Old Army Colonel And His Son Often Hiccup"
(which gives the functions in the order tangent, cosine, sine).
5. "Studying Our Homework Can Always Help To Obtain Achievement.”

12. Bonus Assignment:
Create a Mnemonic to
remember
SOHCAHTOA