Sine Cosine Tangent Formula

To calculate the angle of a right triangle, sine cosine tangent formula is used. The ratio of the different sides of the triangle gives the sine cosine and tangent angles. Here the hypotenuse is the longest side, the side opposite to the hypotenuse is the opposite side and the where both the sides rests is the adjacent side. A right angle looks like this:

sine cosine

The Sine Cosine Tangent Formula is,

\[\large Sin\;\theta = \frac{Opposite}{Hypotenuse}\]

\[\large cos\;\theta = \frac{Adjacent}{Hypotenuse}\]

\[\large tan\;\theta = \frac{Opposite}{Adjacent}\]

Solved Examples

Question: Calculate the angle in a right triangle whose adjacent side and hypotenuse are 12 cm and 20 cm respectively ?

Adjacent side = 12 cm
Hypotenuse = 20 cm

$cos\; \theta$ = $\frac{Adjacent}{Hypotenuse}$

$cos\; \theta$ = $\frac{12}{20}$

$\theta = cos^{-1}(0.6)$

$\theta = 99.99$ 

Practise This Question

A perpendicular bisector of a given line is perpendicular to it and divides the given line into two parts of equal length.