# 6 SIMPLE STEPS TO MASTERING NORMAL (TECHNICAL) TRIGONOMETRY

Step 1) Know how to identify Hypotenuse, Opposite Side and Adjacent Side.

Step 2) When you see RIGHT- ANGLED TRIANGE in your Maths exam, most likely you will need to use Pythagoras’ Theorem or Sine/Cosine/Tangent Ratio to solve the question.

Step 3) For Pythagoras’s Theorem, make sure you know how to ‘play around with the formula’, C^2=A^2 + B^2. An example looks like this

Find the unknown when

C^2 =8^2 + 6^2

OR

10^2= A^2+ 6^2

Step 4)  The Same for Sine/Cosine/Tangent Ratio, know how to ” play around with the formula”. The question may look like this.

Find X when Tan X= 5/12 or Tan 60= X/12 or Tan 60 = 12/x

An easier way to remember the formula is

TOA CAH SOH aka Big Foot Auntie in Hokien,

TOA= Tan (angle)= Opposite side/ Adjacent side.

SOH= Sin(angle)= Opposite side/ Hypotenuse

Step 5) Before attempting Trigonometric Ratios question, always IDENTIFY THE O,A & H FIRST then you will have a clearer picture of  which formula to use.

Step 6) For Angles of Elevation and Depression and Word Problems involving Trigonometric Ratios, most of the time I’d tell my student to ignore the long winded question, just find out what the question wants; What is the Unknown in that question and use Trigonometric Ratios to solve.

For NT Maths, the question is very straight forward unlike O-level and the diagram will be drawn for you.