GCSE Secondary Maths Age 13-17 - Pythagoras & Trigonometry: Area of a Triangle - Explained

The video tutorial explains how to calculate the area of a non-right angled triangle using the sine rule. It begins with setting up the problem by identifying the given sides and angles. The instructor then uses the sine rule to find the unknown angles, followed by calculating the area of the triangle. The tutorial concludes with a discussion on the marks allocation for the problem and the importance of understanding the sine rule for solving such geometry problems.

What is the length of side PQ in triangle RPQ?

• 5.2 cm

• 32 cm

• 8.7 cm

• 62 cm

Which formula is used to calculate the area of a non-right-angled triangle?

• Pythagorean theorem

• Sine rule for area

• Heron's formula

• Cosine rule

What is the value of angle Q calculated using the sine rule?

• 90 degrees

• 85.55 degrees

• 62.448 degrees

• 32 degrees

How do you calculate the area of triangle RPQ using the sine rule?

• 1/2 * base * height

• AB * sin(C)

• 1/2 * AB * sin(C)

• 1/2 * (a + b + c)

What is the final area of triangle RPQ rounded to three significant figures?

• 22.6 cm²

• 21.5 cm²

• 22.5 cm²

• 23.0 cm²

What would be the effect on the area calculation if angle PQR was obtuse?

• The area would be larger

• The area would remain the same

• The area would be smaller

• The area cannot be determined

How many marks were allocated for the process of finding the area of the triangle?

• 4 marks

• 3 marks

• 2 marks

• 1 mark