# DIFF between TOA CAH SOH and the RULES!!?? HELP!!!

• Jan 30th 2006, 11:44 PM
xiaoz
DIFF between TOA CAH SOH and the RULES!!?? HELP!!!
Why do we need to use the SINE RULE, when we have learnt TOA CAH SOH? :confused:

TOA CAH SOH is use to solve what? And SINE RULE is use to solve what? :confused:

can anyone tell mi plz.. :(
• Jan 31st 2006, 01:06 AM
TD!
TOA CAH SOH only holds in a right triangle, the sine (and cosine) rule are valid in an arbitrary triangle.
• Jan 31st 2006, 02:56 AM
xiaoz
THXz.. but i still abit dun get it.. =.="
• Jan 31st 2006, 03:29 AM
jacs
TOH CAH SOH is for use only in right angled triangles.

For non-right angled triangles we can find an unknown side (providing we have two angles and another side)

$\displaystyle \frac{a}{sinA} = \frac{b}{sinB}= \frac{c}{sinC}$

or if you are looking for an unknown angle (with two sides known and one angle then use

$\displaystyle \frac{sinA}{a} = \frac{sinB}{b} = \frac{sinC}{c}$
• Jan 31st 2006, 04:36 AM
xiaoz
... then i more confuse le.. cos i am the 1 asking~~ =.= :confused:

the poly ppl should no rite? :eek: