## How are sin values derived?

To find the value of sin 30 degree, we will use the following formula, Sinϴ = Perpendicular Hypotenuse. Thus, the value of Sin 30 degrees is equal to 12(half) or 0.5. Just like the way we derived the value of sin 30 degrees, we can derive the value of sin degrees like 0°, 30°, 45°, 60°, 90°,180°, 270° and 360°.

**Who came up with sine?**

Sine was introduced by Abu’l Wafa in 8th century, as a more convenient function, and gradually spread first in the Muslim world, and then to the West. (But apparently it was used in India centuries before him), as a more convenient function. However this new notation was adopted very slowly, it took centuries.

**How are the values of sin cos and tan derived?**

Sine θ = Opposite side/Hypotenuse = BC/AC. Cos θ = Adjacent side/Hypotenuse = AB/AC. Tan θ = Opposite side/Adjacent side = BC/AB.

### Why do we need sine rule?

The sine rule (or the law of sines) is a relationship between the size of an angle in a triangle and the opposing side. We can use the sine rule to work out a missing angle or side in a triangle when we have information about an angle and the side opposite it, and another angle and the side opposite it.

**Why is sine opposite over hypotenuse?**

The sine is always the measure of the opposite side divided by the measure of the hypotenuse. Because the hypotenuse is always the longest side, the number on the bottom of the ratio will always be larger than that on the top.

**How to calculate law of sines?**

– You only know the angle α and sides a and c; – Angle α is acute ( α < 90° ); – a is shorter than c ( a < c ); – a is longer than the altitude h from angle β, where h = c * sin (α) (or a > c * sin (α) ).

#### When to use law of sines?

– AAS: two angles are known, and a side which is not between them. – ASA: two angles are known, and the side between them. The third angle can be found using the rule for the sum of angles, and this angle must be opposite – SSA: two sides are known, and an angle which is not between them.

**What does law of sines stand for?**

Law of Sines. The Law of Sines is the relationship between the sides and angles of non-right (oblique) triangles . Simply, it states that the ratio of the length of a side of a triangle to the sine of the angle opposite that side is the same for all sides and angles in a given triangle. In Δ A B C is an oblique triangle with sides a, b and c

**How do you use the law of sines?**

The opposite side is the side opposite to the angle of interest,in this case side a.