Pythagoras’ Theorem
Overview
Pythagoras' theorem is one of the most useful results in all of mathematics, and one of the most quietly powerful: it ties the three sides of any right-angled triangle together in a single, elegant rule. Once you know it, you can find a length you cannot reach a ruler to, check whether a corner is truly square, or work out the straight-line distance between two points, all without measuring directly.
In this lesson you will meet the theorem itself, learn to spot the all-important hypotenuse, and practise the two skills examiners ask for again and again: finding the longest side, and finding one of the shorter sides. You will see it solve real problems (ladders, screens, ramps and routes), find out where students most often slip up, and pick up the exam habits that turn a correct method into full marks.
Objectives
- Know and use Pythagoras’ theorem.
Audio Lesson
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Mind map
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Flashcards
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Lesson Note
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Lesson Evaluation
Congratulations on completing the lesson on Pythagoras’ Theorem. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.
You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.
Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.
- In a right-angled triangle, which side is the hypotenuse? A. The shortest side B. The side opposite the right angle C. Either of the two sides that meet at the right angle D. The side at the top of the triangle Answer: B
- A right-angled triangle has shorter sides of 9 cm and 12 cm. Find the length of the hypotenuse. A. 13 cm B. 15 cm C. 21 cm D. 225 cm Answer: B
- The hypotenuse of a right-angled triangle is 25 cm and one shorter side is 7 cm. Find the other shorter side. A. 18 cm B. 24 cm C. 32 cm D. 576 cm Answer: B
- Which set of side lengths forms a right-angled triangle? A. 2 cm, 3 cm, 4 cm B. 5 cm, 6 cm, 8 cm C. 8 cm, 15 cm, 17 cm D. 6 cm, 7 cm, 9 cm Answer: C
- Pythagoras' theorem can be applied to: A. Any triangle B. Only right-angled triangles C. Only equilateral triangles D. Only isosceles triangles Answer: B
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