Law of Sines and Angles

Dr. En van Leen from Curtin University explains how to solve non-right angle triangles using the sine rule. The video covers the conditions for applying the sine rule, provides a detailed example, and discusses the possibility of multiple solutions for angle B. It concludes with a summary of when to use the sine and cosine rules.

What is the primary focus of the video tutorial?

• Solving right-angle triangles

• Understanding the Law of Sines and Cosines

• Learning about algebraic equations

• Exploring calculus concepts

When should the Law of Sines be used?

• When no angles are known

• When two angles and a side are known

• When two sides and the enclosed angle are known

• When all side lengths are known

What does the Law of Sines mathematically state?

• A side length is proportional to the cosine of its opposite angle

• A side length is equal to the tangent of its opposite angle

• A side length is proportional to the sine of its opposite angle

• A side length is equal to the cosine of its opposite angle

In the example, what is the first step to solve the triangle?

• Calculate the length of side C

• Determine the angle at B

• Find the area of the triangle

• Calculate the perimeter of the triangle

What is the calculated angle B in the first solution?

• 154.32 degrees

• 21 degrees

• 25.8 degrees

• 133.2 degrees

Why is there a second possible solution for angle B?

• Because the cosine function is periodic

• Because the sine function is periodic

• Because the tangent function is periodic

• Because the angle is greater than 90 degrees

What is the second possible angle B?

• 133.2 degrees

• 25.8 degrees

• 21 degrees

• 154.32 degrees

In the first case, what is the remaining angle C?

• 133.2 degrees

• 154.32 degrees

• 25.8 degrees

• 21 degrees

How is the side length C calculated in the first case?

• Using the tangent rule

• Using the Pythagorean theorem

• Using the sine rule

• Using the cosine rule

In the second case, what is the remaining angle C?

• 154.32 degrees

• 25.8 degrees

• 133.2 degrees

• 4.8 degrees