Law of Sines and Cosines

Front

What is the Law of Sines?

Back

Sin(A)/a = Sin(B)/b = Sin(C)/c

Front

When do you use the Law of Sines?

Back

Use the Law of Sines when you have either two angles and one side (AAS or ASA) or two sides and a non-included angle (SSA).

Front

What is the Law of Cosines?

Back

c² = a² + b² - 2ab * cos(C) for triangle ABC.

Front

When do you use the Law of Cosines?

Back

Use the Law of Cosines when you have two sides and the included angle (SAS) or all three sides (SSS).

Front

Find the length of side AB. m<C = 53 degrees, m<B = 44 degrees, AC = 7.

Back

AB = 8.0

Front

Which Law would you use to find side length BC?

Back

Law of Sines

Front

What is the measure of angle A if BC = 37 cm, AB = 29 cm and m<C = 50 degrees?

Back

Angle A = 77.8 degrees

Front

What is the relationship between the sides and angles in a triangle according to the Law of Sines?

Back

The ratio of the length of a side to the sine of its opposite angle is constant.

Front

What is the formula for finding an angle using the Law of Cosines?

Back

cos(C) = (a² + b² - c²) / (2ab) for angle C.

Front

What is the sine of an angle in a right triangle?

Back

Sine = opposite side / hypotenuse.