Triangle Problem Solving Techniques

The video tutorial explores solving a triangle problem by finding missing angles and sides. It begins with labeling the triangle's sides and using the cosine rule to calculate side a. The instructor then attempts to find angle c using the sine rule, encountering an error due to the obtuse nature of the angle. The error is corrected by applying the cosine rule, which is more suitable for obtuse angles. The lesson concludes with insights on when to use cosine and sine rules effectively.

What is the main objective of the video tutorial?

• To calculate the area of a triangle

• To learn how to draw triangles accurately

• To find missing angles and sides of a triangle

• To understand the history of trigonometry

What is the first step taken in solving the triangle problem?

• Drawing the triangle accurately

• Labeling the sides

• Finding the perimeter

• Calculating the area

Why can't the sine rule be used initially?

• Because the sides are not labeled

• Because there is no pair of angles and sides

• Because the angles are not given

• Because the triangle is not right-angled

Which rule is used to calculate side 'a'?

• Tangent rule

• Sine rule

• Cosine rule

• Pythagorean theorem

What is the calculated length of side 'a' to three significant figures?

• 58.8 meters

• 26 meters

• 105 meters

• 131 meters

What is the potential issue with the diagram drawn?

• It has missing sides

• It is not drawn to scale

• It uses incorrect labels

• It is not a triangle

What angle is initially calculated using the sine rule?

• Angle D

• Angle C

• Angle B

• Angle A

What discrepancy is found when using the sine rule?

• The angle calculated is zero

• The angle calculated is right

• The angle calculated is acute

• The angle calculated is obtuse

What rule is used to re-evaluate angle C?

• Sine rule

• Cosine rule

• Tangent rule

• Pythagorean theorem

What is the correct value of angle C using the cosine rule?

• 51.5 degrees

• 26 degrees

• 77.5 degrees

• 102.5 degrees