The Law of Sines & Cosines

Front

What is the Law of Cosines formula?

Back

c² = a² + b² - 2ab cos(C)

Front

What is the Law of Sines formula?

Back

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

Front

When is the Law of Cosines used?

Back

It is used when you have either SSS (three sides) or SAS (two sides and the included angle) to solve for unknown sides or angles in a triangle.

Front

What does SSS stand for in triangle solving?

Back

SSS stands for Side-Side-Side, indicating that all three sides of a triangle are known.

Front

What does SAS stand for in triangle solving?

Back

SAS stands for Side-Angle-Side, indicating that two sides and the included angle are known.

Front

How do you find the length of a side using the Law of Cosines?

Back

You can rearrange the Law of Cosines formula to solve for the unknown side.

Front

What is the relationship between the angles and sides in the Law of Sines?

Back

The ratio of the length of a side to the sine of its opposite angle is constant for all three sides and angles.

Front

What is the first step in using the Law of Sines to find an unknown angle?

Back

Identify a known side and its opposite angle, then set up the ratio with the unknown side and angle.

Front

What is the significance of the angle in the Law of Cosines?

Back

The angle is used to determine the relationship between the sides of the triangle, affecting the calculation of unknown sides.

Front

How can you determine if a triangle is solvable using the Law of Cosines?

Back

Check if you have either three sides (SSS) or two sides and the included angle (SAS).