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
Having sufficient angles or sides one can use either, The Law of Sines, or, The Law of Cosines. Google them.
Yes
The law of cosines and sines can always be used to solve problems involving triangles, specifically when dealing with non-right triangles. The law of cosines is applicable for finding a side or angle when you know either two sides and the included angle or all three sides. The law of sines can be used when you have two angles and one side (AAS or ASA) or two sides and a non-included angle (SSA). Both laws are essential in solving triangle problems in various applications, including navigation and physics.
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.
Either.However, if you know two sides and the includedangle then the sine rule is simpler.
cosine = adjacent/hypotenuse
Having sufficient angles or sides one can use either, The Law of Sines, or, The Law of Cosines. Google them.
Yes
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.
D. The Pythagorean Theorem
Yes
Yes, absolutely
Acute triangle - all of the angles are less than a right angle (90°).Scalene triangle - none of the sides or angles are congruent. It can be shown that if no two angles are the same, then no two sides are the same using the Law of Sines and Law of Cosines.
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.
Either.However, if you know two sides and the includedangle then the sine rule is simpler.
true
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.