This is a lesson I used for a recent observation in Year 3 (it's also relevant for Year 4) in which I was graded 'outstanding'. It teaches children to classify angles into acute, right and obtuse with a cross-curricular link to Science (angles of light). A lesson plan complete with all the activities, worksheets, resources and clear visual presentation is included. The lesson has a higher ability starter where they must work out missing number problems in context (missing angles within right angles.) Because they are multi-step problems they can be used evidence of greater depth learners. Thanks for looking. For more quality maths resources, please see my shop by following the link below: https://www.tes.com/teaching-resources/shop/d_roberts1