Pythagoras Theorem — Interactive Lesson (Ages 14–16)

Never sure whether to add or subtract the squares? This 31-slide interactive lesson takes students step by step through Pythagoras theorem, with worked examples and self-marking practice on right-angled triangles.

Mastering Pythagoras Theorem in Year 10–11 Maths

Students begin by naming the three key sides of a right-angled triangle, then meet the formula c² = a² + b² and learn why the hypotenuse is always the longest side. Worked examples show how to test whether a triangle is right-angled, how to find the hypotenuse, and how to rearrange the formula to find a missing shorter side. The lesson closes by using Pythagoras theorem to find the distance between two coordinate points.

What’s Included

• 31-slide interactive lesson with worked examples
• Clear learning objectives, from naming the sides to real-world problems
• Worked examples: testing for a right angle, finding the hypotenuse and finding a shorter side
• 19 self-marking quiz questions, plus a fill-in-the-blanks task and a sorting activity
• A coordinate example finding the distance between two points

Key Benefits for Students

• Shows exactly when to add and when to subtract the squares
• Instant feedback on every quiz question
• Builds the method step by step, from naming sides to applying the formula
• Links right-angled triangles to coordinates

Why Teachers Love It

• No prep — ready for whole-class teaching on an interactive whiteboard
• Self-marking questions support independent practice and homework
• Worked examples model how to set out each calculation
• A dependable foundation before moving on to trigonometry

Love this? You’ll love…

• Trigonometry: Finding lengths and Angles — Interactive Lesson (KS4)
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A dependable addition to a geometry topic, giving students a secure grasp of the theorem before they meet trigonometry. The same right-angled triangle ideas return in coordinate geometry and problem solving.

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FAQ

What year group is this for? Years 10–11 (ages 14–16).

Does it cover finding a missing shorter side? Yes — worked examples cover both the hypotenuse and a shorter side.

Is it self-marking? Yes, with instant feedback on the quiz questions.