The tricky part of the law of sines is knowing when you are able to use it. Whether you can use the law of Sine's or not depends on what information you have or were given. In some cases the information you were given could make two different triangles. There are three times when you can use the law of sines. One example of when you can use it is when you have the length of a side and the measures of both the angles that that side is adjacent to. This is called angle side angle or asa for short. Another time when you can use the law of sines is when you are given the measures of two angles and a side that is outside the angles. This is called aas. Finally the last case where you can use the law of sines is when you have two side lengths and the measure of an angle. Math teachers refer to this one as ssa, I remember that this one is special. If you are given the measure of an angle and two sides you could have two different triangles.
Having sufficient angles or sides one can use either, The Law of Sines, or, The Law of Cosines. Google them.
Use the law of sines.
If you have two other angles, then add up those 2 and subtract that from 180. if you have all 3 sides then use the law of cosines: a squared = b squared + c squared - 2bc (cos A) If you have one angle and the 2 included sides, use the law of cosines as well. if you have an angle and the length of its opposite side, and the side opposite to the angle you want, then use the law of sines: sin A/ a = sin B/ b if you have the angle and the length of its opposite side and another angle, use the law of sines to figure out the unwanted angle anyway and then follow situation 1.
Trigonometric ratios, by themselves, can only be used for right angled triangles. The law of cosines or the sine law can be used for any triangle.
The tricky part of the law of sines is knowing when you are able to use it. Whether you can use the law of Sine's or not depends on what information you have or were given. In some cases the information you were given could make two different triangles. There are three times when you can use the law of sines. One example of when you can use it is when you have the length of a side and the measures of both the angles that that side is adjacent to. This is called angle side angle or asa for short. Another time when you can use the law of sines is when you are given the measures of two angles and a side that is outside the angles. This is called aas. Finally the last case where you can use the law of sines is when you have two side lengths and the measure of an angle. Math teachers refer to this one as ssa, I remember that this one is special. If you are given the measure of an angle and two sides you could have two different triangles.
The tricky part of the law of sines is knowing when you are able to use it. Whether you can use the law of Sine's or not depends on what information you have or were given. In some cases the information you were given could make two different triangles. There are three times when you can use the law of sines. One example of when you can use it is when you have the length of a side and the measures of both the angles that that side is adjacent to. This is called angle side angle or asa for short. Another time when you can use the law of sines is when you are given the measures of two angles and a side that is outside the angles. This is called aas. Finally the last case where you can use the law of sines is when you have two side lengths and the measure of an angle. Math teachers refer to this one as ssa, I remember that this one is special. If you are given the measure of an angle and two sides you could have two different triangles.
Having sufficient angles or sides one can use either, The Law of Sines, or, The Law of Cosines. Google them.
If you have the length of two of the sides and one other angle you can use the law of sines.
There are several cases when you would want to use the law of sines. When you have angle angle side, angle side angle, or angle side side you would use the law of sines.
Use Law of Sines if you know:Two angle measures and any side length orTwo side lengths and a non-included angle measure.Use Law of Cosines if you know:Two side lengths and the included angle measure orThree side lengths.
Use the law of sines.
The Law of Sines can be used to find unknown parts (a side or angle) of a triangle. For example if you know 2 angles and a side, or if you know 2 sides and 1 angle (depending on how they are oriented). Visit the Maths Is Fun site (link posted below) for a more graphical explanation.
If you have two other angles, then add up those 2 and subtract that from 180. if you have all 3 sides then use the law of cosines: a squared = b squared + c squared - 2bc (cos A) If you have one angle and the 2 included sides, use the law of cosines as well. if you have an angle and the length of its opposite side, and the side opposite to the angle you want, then use the law of sines: sin A/ a = sin B/ b if you have the angle and the length of its opposite side and another angle, use the law of sines to figure out the unwanted angle anyway and then follow situation 1.
no #9
if it is a right triangle, use pythagorean theorem: a2+b2=c2 if not, and you have one of the angles, use law of sines: sinA/a=sinB/b=sinC/c
If you have all three angles, you can use the law of sines, which states that the ratio of the sine of one angle is to it's opposite side as the sine of another angle is to it's opposite side.