To solve a triangle when you are given 3 sides, you would use the law of? is it cosine?

Answer 1

You can use Heron's formula to get the area... is that what you mean?

First take the semi-perimeter (half the sum of the sides).

So if you had a triangle with sides of 6, 8 and 10, the semi-perimeter would be:
(s1 + s2 + s3) / 2
(6 + 8 + 10) / 2 = 12

Now put that in the following formula:
A = sqrt( s (s - s1)(s - s2)(s - s3) )
A = sqrt( 12 (6)(4)(2) )
A = sqrt( 576 )
A = 24 sq. units.

Answer 2

You can only use the law of cosines if the triangle given has at least one oblique angle.. You can also solve it using sine law if one angle is oblique.. but if it has a right angle in it, you can use pythagorean theorem or heron's law.. You should know first what type of triangle is it..

Answer 3

You use the law of cosine to solve for one angle, then use the law of sine after. Here is a link that can help you:
http://www.teacherschoice.com.au/Maths_Library/Trigonometry/solve_trig_SSS.htm

Answer 4

You can use Heron's formula to get the area and the Law of Cosines to get the angles.

Answer 5

yeah cosine law

Answer 6

Yes

a^2 + b^2 - 2ab(cos(C)) = c^2
b^2 + c^2 - 2bc(cos(A)) = a^2
a^2 + c^2 - 2ac(cos(B)) = b^2

using that will give you angle A, B, and C