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If you have all sides of a triangle how do you use the law of cosines to solve the angles?
Wiki User
∙ 14y ago
Label the angles of the triangle A, B, and C. Label the side opposite angle A side a, the one opposite angle B side b, and the one opposite angle C side c.
Let's say you want to solve for angle A, you use the law of cosines:
a^2=b^2+c^2-2bcCosA
CosA is the "variable" in this equation, so isolate this. When you have that, you'll have some number (let's call it D) equal to CosA:
D=CosA
Use the inverse Cos function to find the measure of the angle:
Cos^-1(D)=A
And you have the measure of angle A.
From here you can either use the law of cosines again to find a second angle and then the third, though the easier route is usually to just use the law of sines for find the second angle and then the fact that all three angles add to 180 to find the third.
Wiki User
∙ 14y ago
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In trigonometry sines and cosines are used to solve a mathematical problem. And sines and cosines are also used in meteorology in estimating the height of the clouds.
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What does it mean to ''solve a triangle''?
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Is this statement true or falseYou can use the Law of Cosines to solve a triangle when you are given the lengths of the three sides and no angle measures?
true
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By using the cosine rule in trigonometry the angles of the triangle can be worked out.
How do you figure out the length of one side of a triangle with the length of other two sides?
C^2=A^2+B^2. Pythagorean theorem. Note that this is only true for Right triangles (one of the angles is 90°). Side C is the longest side and is opposite the 90° angle. For any other triangle, you need at least 3 pieces of information (2 sides and an angle, or 2 angles and a side) to find the other parts of the triangle. In a right triangle, if you know 2 sides, then you have 3 pieces of info (one of the angles is 90°). For non-right triangles, you can use the Law of Sines or Law of Cosines to solve for the unknown information.
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Yes, absolutely
Explain how to solve the area of this triangle?
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