How to use the law of cosines with your calculator (SAS)

The video tutorial guides students through solving a triangle problem using trigonometric laws. It begins with setting up the problem and identifying the known elements of the triangle. The instructor then demonstrates the application of the Law of Cosines to find unknown sides and angles, emphasizing the importance of order of operations and calculator use. The tutorial also discusses the Law of Sines, highlighting its limitations in certain cases. The session concludes with final calculations and a review of the results, ensuring students understand the process and theorems used.

What is the significance of the side-angle-side (SAS) method in triangle congruency?

• It helps in identifying the type of triangle.

• It proves the congruency of two triangles.

• It is used to calculate the area of a triangle.

• It determines the perimeter of a triangle.

Why is the Law of Cosines preferred over the Law of Sines in this scenario?

• Because it provides more accurate results.

• Because it is easier to use.

• Because it requires fewer calculations.

• Because the necessary ratio for the Law of Sines is not available.

What is a common mistake students make when using calculators for trigonometric calculations?

• Not using the correct mode.

• Typing in the wrong numbers.

• Not following the order of operations.

• Forgetting to use parentheses.

What should you do after calculating a squared value in trigonometry?

• Take the square root of the value.

• Subtract it from the other sides.

• Add it to the other sides.

• Multiply it by the cosine of the angle.

Why is it important to store calculated values in a calculator?

• To save time in future calculations.

• To ensure accuracy by avoiding rounding errors.

• To make the calculator run faster.

• To prevent the calculator from resetting.

What is the main issue with using the Law of Sines in this context?

• It requires more complex calculations.

• It can lead to ambiguous cases.

• It is not applicable to obtuse triangles.

• It does not work with acute angles.

How can you find the remaining angle in a triangle after finding two angles?

• By subtracting the sum of the known angles from 180 degrees.

• By using the Law of Cosines.

• By using the Law of Sines.

• By adding the known angles together.

What does the hinge theorem help verify in a triangle?

• The type of triangle.

• The congruency of two triangles.

• The relationship between angles and sides.

• The area of the triangle.

Why is it important not to use rounded answers in intermediate calculations?

• It can lead to incorrect final results.

• It is easier to remember.

• It makes the process faster.

• It simplifies the calculations.

What should you be careful about when typing calculations into a calculator?

• Using the correct mode.

• Typing slowly.

• Checking the battery level.

• Using parentheses correctly.