GCSE Secondary Maths Age 13-17 - Pythagoras & Trigonometry: The Sine and Cosine Rules - Explained

The video tutorial explains how to calculate the length of a line segment in a non-right angled triangle using the sine and cosine rules. It starts with setting up the problem, then applies the sine rule to find one side of a triangle, and the cosine rule to find the desired length. The tutorial concludes with a breakdown of marks and advice on using calculators effectively.

What additional information is needed to calculate the length of AD in the given problem?

• The length of DB

• The angle at D

• The angle at C

• The length of AB

Which rule is used to find the length of DB in triangle BDC?

• Cosine rule

• Sine rule

• Tangent rule

• Pythagorean theorem

What is the calculated length of DB using the sine rule?

• 11.4 cm

• 12.5 cm

• 7.39 cm

• 13.1 cm

In which scenario is the cosine rule applicable?

• When all sides are equal

• When all angles are known

• When only one angle is known

• When two sides and the included angle are known

What is the final length of AD calculated using the cosine rule?

• 14.2 cm

• 13.1 cm

• 12.5 cm

• 11.4 cm

What is the importance of using the full display of the calculator during calculations?

• To save time

• To ensure accuracy

• To simplify the process

• To avoid using memory

What is the key takeaway regarding the use of sine and cosine rules?

• They are not necessary for solving triangle problems

• Understanding when to use each rule is crucial

• They are only used for right-angled triangles

• They are interchangeable