11/14/22 - Laws of Cosines and Sines

Question 1

What is the Law of Cosines?

Answer 1

Given a triangle with sides a, b, and c and angle θ opposite side c,
c^2 = a^2 + b^2 - 2ab(cos θ)

Question 2

What is the Law of Sines?

Answer 2

Given a non-right triangle with sides a, b, and c and angles A, B, and C,
sin(A)/a = sin(B)/b = sin(C)/c

Question 3

When should you use the Law of Cosines?

Answer 3

When the problem involves 3 sides and 1 angle.

Question 4

When should you use the Law of Sines?

Answer 4

When the problem involves 2 sides and 2 angles.