1. TRIG – THE EASY WAY

2. Trig functions
To remember the trigonometry functions, use the memory aid:
Soh Cah Toa
The first letter of each aid represents the function. The last two letters indicates the ratio of sides needed to calculate the function.
Soh --> Sine = opposite/hypotenuse
Cah --> Cosine = adjacent/hypotenuse
Toa --> Tangent = opposite/adjacent
We can use trigonometry functions to determine:
• one acute angle if you know two sides
• one of the sides if you know an acute angle and one side

3. HYPOTENUSE, OPP. LEG, & ADJ. LEG

4. TO FIND A MISSING SIDE 21 ?
42°

5. THE PROCESS Determine what trig function to use
Set up the equation that solves the situation
Solve the equation and round answer appropriately 21 ?
42°

6. DETERMINING THE FUNCTION
hypotenuse 21 ?
Opp
42°
Opposite / hypotenuse >>>>>>>>> SINE

7. solution Sin 42° = x / 21 .6691 = x / 21 X = (.6691) (21) X= 14.0511

8. TO FIND A MISSING ANGLE 8 ? 15

9. DETERMINE THE FUNCTION.
OPPOSITE 8 ? 15
ADJACENT
OPPOSITE / ADJACENT >>>>>>>>> TANGENT

10. PROCESS AND SOLUTION ‹D = tan-1(0.5333) ‹D = 28.072487 ‹D = 28º
Determine the function ----> Tangent
Write the equation > Tan D = 8 / 15
Solve the equation > Tan D = .5333
Note : you must use the inverse of tangent to find the angle:
tan-1 or arctan on your calculator.
‹D = tan-1(0.5333)
‹D =
‹D = 28º