GCSE Secondary Maths Age 13-17 - Pythagoras & Trigonometry: Area and Mass - Explained

The video tutorial explores whether Triangle ABC is a right-angled triangle using Pythagoras theorem. The triangle has a perimeter of 20 cm, with sides AB = 7 cm and BC = 4 cm. The third side, AC, is calculated to be 9 cm. By applying Pythagoras theorem, it is determined that the triangle is not right-angled, as the sum of the squares of the two shorter sides does not equal the square of the longest side. The tutorial also discusses the allocation of marks for solving this problem.

What is the perimeter of Triangle ABC?

• 15 centimeters

• 30 centimeters

• 20 centimeters

• 25 centimeters

How long is side AB of Triangle ABC?

• 4 centimeters

• 5 centimeters

• 7 centimeters

• 6 centimeters

What is the length of side AC after calculation?

• 10 centimeters

• 9 centimeters

• 8 centimeters

• 7 centimeters

Which theorem is used to determine if Triangle ABC is right-angled?

• Pythagoras' Theorem

• Thales' Theorem

• Euclid's Theorem

• Archimedes' Principle

What is the conclusion about Triangle ABC being right-angled?

• It is not a right-angled triangle.

• It is a right-angled triangle.

• It is an equilateral triangle.

• It is an isosceles triangle.