# When to use law of cosines and law of sines

## When can law of sines be used?

The law of sines can be used to compute the remaining sides of a triangle when two angles and a side are known—a technique known as triangulation. It can also be used when two sides and one of the non-enclosed angles are known.

## When would you use the law of sines to solve a triangle?

The law of sines is used to solve triangles in which you know only two angles and one of the opposing sides (called AAS for angle-angle-side), or two sides and one of the opposing angles (called SSA for side-side-angle).

## Do you need a right triangle to use law of sines?

The Law of Sines says that in any given triangle, the ratio of any side length to the sine of its opposite angle is the same for all three sides of the triangle. This is true for any triangle, not just right triangles. Press ‘reset’ in the diagram above.

## What is the law of Triangle?

Statement: If two vectors are represented by the sides of a triangle both in magnitude and direction taken in order, the resultant sum of the vectors is given by the closing third side of the triangle taken in the reverse order both in the magnitude and direction.

## What is the law of sines equation?

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 ΔABC is an oblique triangle with sides a,b and c , then asinA=bsinB=csinC .

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## What is the law of cosines used for?

The law of cosines allows us to find angle (or side length) measurements for triangles other than right triangles. The third side in the example given would ONLY = 15 if the angle between the two sides was 90 degrees. In the example in the video, the angle between the two sides is NOT 90 degrees; it’s 87.

## What is an SSS triangle?

“SSS” means “Side, Side, Side” “SSS” is when we know three sides of the triangle, and want to find the missing angles. To solve an SSS triangle: use The Law of Cosines first to calculate one of the angles. then use The Law of Cosines again to find another angle.

## Why does the law of sines not always work?

Cases when you can not use the Law of Sines

Since we do not know an opposite side and angle, we cannot employ the formula. Or, just look at it: Remember when you have 2 sides, the angle must be non-included. By the way, we could use the law of cosines to find the length of the side opposite the 115° angle.

## How do you use the law of cosines?

When to Use

The Law of Cosines is useful for finding: the third side of a triangle when we know two sides and the angle between them (like the example above) the angles of a triangle when we know all three sides (as in the following example)

## Do trigonometric functions only work for right triangles?

Explanation: Although most often trigonometric functions are used with right triangles there are some situations when they can be used for any type of triangle. … If you have two sides given and an angle between them you can use the trigonometric functions the Law of Cosines to calculate the third side.4 мая 2017 г.

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## Where is angle of depression?

The angle of depression is the angle between the horizontal line of sight and the line of sight down to an object. For example, if you were standing on top of a hill or a building, looking down at an object, you could measure the angle of depression.

## What are the 3 sides of a triangle called?

In a right triangle, the hypotenuse is the longest side, an “opposite” side is the one across from a given angle, and an “adjacent” side is next to a given angle. We use special words to describe the sides of right triangles.

## Is current is a vector quantity?

Electric current is a scalar quantity. Any physical quantity is termed as a vector quantity when the quantity has magnitude and direction. … In the case of electric current, when two currents meet at a junction, the resultant current of these will be an algebraic sum and not the vector sum.