Question

Describe how to find the sine, the cosine, and the tangent of an angle?

Answer 1

https://www.khanacademy.org/math/trigonometry/basic-trigonometry/basic_trig_ratios/v/basic-trigonometry

Answer 2

The ratios for finding the sine, cosine, and tangent of an angle are as follows: opposite/hypotenuse, adjacent/hypotenuse, and opposite/adjacent, respectively. This is in reference to a right triangle where each name is the sides location relative to the angle you are finding.

Answer 3

Suppose you have a triangle ABC with C a right-angle, angle CBA=x, CB=a in length, AB=h
and CA=o. [These are labelled o,a and h to the sides opposite (o), adjacent (a) to x and
hypotenuse (h).]
Then sinx=o/h, cosx=a/h, tanx=o/a
If o=5 cm, a=12 cm and h=13 cm and you are looking for angle x you could use any of sin. cos
or tan. If tan, then tanx=5/12 =0.4167
Use the tan^-1 button on your calculator to give x= 22.6 degrees.

The special triangle is an equilateral triangle of side 2, split down the middle
to give ABX where AB=2, BX=1 and by Pythagoras, AX=sqrt(3)
Note that angle B=60°, angle BAX=30°, AXB=90
For x= 60°, mark side 2 as h, side 1 as a and side 0 as sqrt(3)
You can write down sin cos and tan 60° using the above definitions.
Now draw the same triangle but with x=30°, and corresponding o and a.
You can now write down sin,cos,tan 30°.
For this triangle have a right-angled isosceles triangle with equal sides 1 and hypotenuse sqrt(2).
The equal angles are 45°.
For sin, cos, tan 45° mark sides o,a and h as above and find sin, cos, tan as above.




http://www.mathwarehouse.com/trigonometry/sine-cosine-tangent.php







The sine function, along with cosine and tangent, is one of the three most common trigonometric functions. In any right triangle, the sine of an angle x is the length of the opposite side (O) divided by the length of the hypotenuse (H). In a formula, it is written as 'sin' without the 'e':

Often remembered as "SOH" - meaning Sine is Opposite over Hypotenuse