Basic Trigonometry

1
Basic Trigonometry

• An Introduction

2
Right Triangle Anatomy

• The legs are the 2 sides that form the right
  angle
• The side opposite the right angle is called the
  hypotenuse.

hypotenuse
leg
leg
3
Trigonometry
4
Ratio Definitions

• Sin opposite leg / hypotenuse
• Cos adjacent leg / hypotenuse
• Tan opposite leg / adjacent leg

5
Reciprocals
6
Reciprocal Ratio Definitions

• Cot 1 / Tan
• Sec 1 / Cos
• Csc 1 / Sin

7
Alternate Reciprocal Definitions

• Cot adjacent leg / opposite leg
• Sec hypotenuse / adjacent leg
• Csc hypotenuse / opposite leg

8
Examples
Y

• Sin X b / c
• Cos X a / c
• Tan X b / a

C
b
X
a
9
Reciprocal Examples
Y

• Cot X a / b
• Sec X c / a
• Csc X c /b

c
b
X
a