Because that is accepted definition. The sine is opposite over hypotenuse, or Y in the unit circle. The cosine is adjacent over hypotenuse, or X in the unit circle. The tangent is sine over cosine, etc. For more information, please see the related link below.
It is the sine ratio.
It is the Sine(Sin) ratio. Sin(angle) = o/h
If you have a right triangle, the sine of an angle is the ratio of the opposite side to the hypotenuse.
This ratio is called the sine ratio for a right triangle. A simple way to remember this is by using the mnemonic 'SOHCAHTOA', where SOH stands for sine equals the ratio opposite side/ hypotenuse, COH is cosine equals adjacent side/hypotenuse, and TOA is tangent equals opposite side/adjacent side.
Sine ratio = opposite/hypotenuse
sine
Opposite over hypotenuse. Sin=opposite/hypotenuse cos=adjacent/hypotenuse tan=opposite/adjacent
It is the sine ratio.
The sine of an angle in a right triangle is the ratio of the length of the side opposite the angle to the length of the hypotenuse.In terms of ratios, the sine of an angle is defined, in a right angled triangle, as the ratio of lengths of the opposite side to the hypotenuse.
It is the Sine(Sin) ratio. Sin(angle) = o/h
Sine = opposite / hypotenuse
False because sine ratio = opposite/hypotenuse
a) sine
If you have a right triangle, the sine of an angle is the ratio of the opposite side to the hypotenuse.
It is the 'sine' ratio for a right angle triangle
This ratio is called the sine ratio for a right triangle. A simple way to remember this is by using the mnemonic 'SOHCAHTOA', where SOH stands for sine equals the ratio opposite side/ hypotenuse, COH is cosine equals adjacent side/hypotenuse, and TOA is tangent equals opposite side/adjacent side.
In a right triangle, the sine of an (non right angle) angle would the ratio of the opposite side (opposite to the angle selected) and the hypotenuse