Question

How are the ratios defined in a right angle triangle defined?

Answer 1

Trigonometric ratios of the angle A in

right angled triangle ABC are defined

as follows :

Here ,

AC = length of hypotenuse

BC = Length of side opposite to <A

AB = Length of side adjacent to <A



i ) sine of <A = sinA

= BC/AC

ii ) cosine of <A = cos A = AB/AC

iii ) tangent of <A = BC/AB

iv ) Multiplicative inverse of " Sin A " is

" cosecA "

cosecA = 1/sin A = AC/BC

v ) Multiplicative inverse of " cosine "

is " secant A "

secA = 1/cosA = AC/AB

vi ) Multiplicative inverse of " tangent A "

is " cot A "

cot A = 1/tanA = AB/BC

Note :

a ) Each trigonometric ratio is a real

number and has no unit .

b ) " sin A " is one symbol cannot be

separated from A .

c ) If " one of the trigonometric ratios

of an acute angle is known " , the

remaining trigonometric ratios of angle

can be easily determined.

I hope this helps you.

: )