0
Yes because a2 = b2+c2 -2*b*c*cosineA whereas a, b and c are the sides of the triangle with angle A opposite to side a
Wiki User
∙ 10y ago
Add your answer:
Earn +20 pts
Can the law of cosines be used to find a length or just angle?
Either.However, if you know two sides and the includedangle then the sine rule is simpler.
When would you use the law of sines or law of cosines instead of a trigonometric ratio?
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.
How do you find the unknown angle of a triangle?
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.
How do you find a missing side of a triangle without a right angle?
Having sufficient angles or sides one can use either, The Law of Sines, or, The Law of Cosines. Google them.
How do you find the missing angles of a triangle with one?
you must know more information. Like the lengths of 2 sides. Then using Trig (law of sines or law of cosines) you can find the remaining sides and angles.
Can the law of cosines be used to find a length or just angle?
Either.However, if you know two sides and the includedangle then the sine rule is simpler.
When would you use the law of sines or law of cosines instead of a trigonometric ratio?
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.
How do you find the distance between the corner and the center of a rhombus?
You must know something else. Like an angle. Or coordinates of the vertices on an x-y plane. And, of course the length of a side. If you know an angle, then you know them all, adjacent angles are supplementary. use law of cosines to find the length of a diagonal. 1/2 of the diagonal is the distance to the opposite vertices. Use law of cosines with the adjacent angle to find the length of the 2nd diagonal. 1/2 of this 2nd diagonal is the distance from the center to the other two vertices.
Who discovered the law of cosines?
A caveman from 10,000 BCal-Kashi was the 1st to provide an explicit statement of the law of cosines in a form suitable for triangulation
When do you use the Law of Cosines?
We use the law of Cosines to be able to find : 1. The measure of the third side, when the measure of two sides and the included angle of a triangle ABC are known. 2. The measure of any angle, when the measure of the three sides of a triangle ABC are known.
How do you find the unknown angle of a triangle?
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.
How do you find a missing side of a triangle without a right angle?
Having sufficient angles or sides one can use either, The Law of Sines, or, The Law of Cosines. Google them.
How do you calculate the angles of a triangle knowing the sides?
Law of cosines
How do you find the missing angles of a triangle with one?
you must know more information. Like the lengths of 2 sides. Then using Trig (law of sines or law of cosines) you can find the remaining sides and angles.
What are the answers to law of cosines in A plus?
The law of cosines can be written in one form as: c2 = a2 + b2 - 2abCos C. Without 3 of the 4 variables being given, there is no way to answer this question.
Law of cosines with a right angle?
The law of cosines with a right angle is just the pythagorean theorem. The cosine of 90 degrees is 0. That is why the hypotenuse squared is equal to the sum of both of the legs squared
When you have a right angle what does the law of cosines reduce to?
cosine = adjacent/hypotenuse
