Teacher guide · Think Lab · Harder · about 35 min
📐 Angles Explorer
Pupils practise problem solving through "Angles Explorer": Acute, obtuse, right and reflex.
Lesson guide
1. Hook · 5 min
Show the 📐 mission title and read the opening: "An angle of 90° is called…". Take three quick guesses.
2. Model · 5 min
Think aloud through the first step together. Use Cog the Owl's line as your prompt: "Good thinking. Show me the why."
3. Do · 10 min
Pairs work through the 5 steps on screen or on the printed sheet. Circulate and ask "why?"
4. Discuss · 10 min
Use two or three of the discussion questions. Ask pairs to share different answers, not just correct ones.
5. Reflect · 5 min
Exit ticket: one sentence on how they used problem solving today.
Discussion questions
- What was the hardest choice in "Angles Explorer", and why?
- An angle of 90° is called… — explain your reasoning to a partner.
- Angles in a triangle add up to… — explain your reasoning to a partner.
- Two angles of a triangle are 50° and 60°. The third is… — explain your reasoning to a partner.
- Where could you use problem solving outside school this week?
- If you did this again, what would you change?
Adapting it
Support: Read prompts aloud, pair with a confident partner, and accept spoken or drawn answers for writing steps.
Stretch: Ask pupils to create their own extra step for a partner and explain the correct answer.
Curriculum links
- National Curriculum: Maths: number, calculation, fractions and reasoning (KS1/KS2)
- National Curriculum: Maths: reasoning mathematically and problem solving
- National Curriculum: Computing: logical reasoning and algorithms
- PSHE: Living in the wider world: making decisions and evaluating choices
Pupil sheet
📐 Angles Explorer
Name: ____________________ Date: __________
1. An angle of 90° is called…
☐ A right angle
☐ Acute
☐ Obtuse
2. Angles in a triangle add up to…
☐ 180°
☐ 360°
☐ 90°
3. Match the angle to its name.
45° → ________________
120° → ________________
90° → ________________
270° → ________________
4. Two angles of a triangle are 50° and 60°. The third is…
☐ 70°
☐ 80°
☐ 90°
5. Find 3 right angles in your room and describe them.