s er ap eP m e tr .X w w w om .c Scheme of work – Cambridge IGCSE® Mathematics (US) 0444 Unit 4: Geometry (Extended) Recommended prior knowledge All of Core and particularly Core 4. Only those parts of the learning objectives or notes and exemplars not included in the Core units are itemised, so this document should be read alongside the Core document. Context There are five Core geometry units and this is the first of five Extended geometry units. Once Core 4 unit and the other prior experience for Core 4 is completed,this unit can be slotted in at any point. It is probably best taught as a whole but used to revise some of the Core 4 unit. Outline The unit extends the knowledge of Core 4 so be aware that examination questions that relate to aspects of Core 4 may have a greater degree of challenge as they combine with other areas of mathematics. This unit covers understanding the definitions of vocabulary, symmetry in 3D, the additional circle theorem properties, similarity as it affects area and volume, and congruence. Syllabus ref Learning objectives Suggested teaching activities Learning resources 4.1 Vocabulary: Know precise definitions of acute, obtuse, right angle, reflex, equilateral, isosceles, congruent, similar, regular, pentagon, hexagon, octagon, rectangle, square, kite, rhombus, parallelogram, trapezoid, and simple solid figures Line and rotational symmetry in 3D General guidance The difference between this and the core unit is the ‘Know precise definitions’. www.mmlsoft.com/index.php?option=com _content&task=view&id=9&Itemid=10 Ensure students have the definitions and check throughout the unit that they use vocabulary correctly. www.mmlsoft.com/index.php?option=com _content&task=view&id=11&Itemid=12 4.3 v1 2Y01 Teaching activities Use the ‘Tarsia’ software found at ‘mmlsoft’ to create a domino set of definitions and vocabulary and ask students to complete it periodically as a lesson starter. Notes and exemplars Recognize symmetry properties of the prism and the pyramid. Cambridge IGCSE Mathematics (US) 0444 www.youtube.com/watch?v=gBg4lJ19Gg&feature=related 1 Syllabus ref Learning objectives CCSS: G-GCO3 Suggested teaching activities Learning resources General guidance Some students find it very hard to visualize the 3D symmetries. The use of models that can be split or rotated on an axis are vital for them to see what is happening. www.youtube.com/watch?v=cEXx_8FWC sE&feature=related Teaching activities View these two videos and discuss the implications of moving from symmetry in 2D to 3D (points to lines, lines to planes). 4.6 CCSS: G-C1 G-C2 4.7 CCSS: G-SRT2 G-SRT3 G-SRT5 v1 2Y01 Vocabulary of circles Properties of circles: • tangents from a point • angles at the centre and at the circumference on the same arc • cyclic quadrilateral Use the following symmetry properties of a circle: • equal chords are equidistant from the centre • the perpendicular bisector of a chord passes through the centre • tangents from an external point are equal in length Similarity Area and volume scale factors General guidance Showing students the proofs of the circle properties/theorems will add depth to their understanding. However the main requirement is to solve problems that relate to those properties. It is experience and practice that is required, both to select the required facts and to sequence a justification for an answer. http://nrich.maths.org/6007 http://nrich.maths.org/6624 http://nrich.maths.org/2845 http://nrich.maths.org/833 http://nrich.maths.org/599 Teaching activities Students can be given jumbled up lines to a solution and asked to order them. Or in some cases if a series of angles are required students can be challenged to provide more than one route to the complete set and asked to decide which is neatest. www.timdevereux.co.uk/maths/geompage s/index.html The ‘teachnet’ resources provide some sample files that will promote discussion but do not give the theorems themselves in an obvious form. Notes and exemplars Use of the relationships between areas of similar figures and Extended to volumes and surface areas of similar solids. Past Paper 43 June 2011 Q4 (syllabus 0580) Past Paper 22 June 2011 Q13 (syllabus 0580) Past Paper 21 June 2011 Q17 (syllabus 0580) Past Paper 23 June 2011 Q20 (syllabus 0580) www.cimt.plymouth.ac.uk/projects/mepres /book8/bk8i19/bk8_19i3.htm http://nrich.maths.org/6923 General guidance The most difficult aspect for students to grasp is to decide whether the Cambridge IGCSE Mathematics (US) 0444 www.maths4scotland.co.uk/GHS%20Exa 2 Syllabus ref 4.8 CCSS: G-GCO6 G-GCO7 G-GCO8 G-SRT5 Learning objectives Congruence Use the definition of congruence to show that two triangles are congruent if, and only if, corresponding pairs of sides and corresponding pairs of angles are congruent Suggested teaching activities Learning resources particular case is about an area or a volume as the problems can be about 3D objects but the scaling to do with 2D, either because one of the dimensions is fixed or because it is the surface of the object that is the crux of the problem, not its volume. Teaching activities Draw a large triangle. Find the midpoints of two sides (vertex to vertex and pinch the midpoint) and fold the triangle along this line connecting the midpoints. The vertex should touch the opposite side and model nicely that the area of the smaller triangle fits into the larger four times. Ask students to split the sides into thirds along two sides and ask them to fold the top triangle over and construct other lines to show the equivalent numbers of triangles. Ask the general case ‘Can they make diagrams that show this effect for other polygons?’. m%20Revision/GHS%20Credit/Similar%2 0shapes%20%20area%20&%20volume.swf Take students through cases of simple objects like cubes of length 3cm, etc. to prove the squaring and cubing of lengths principal. Notes and exemplars Justify why two triangles are congruent with geometric reasons and reference to ASA, SAS, SSS, or RHS. Justify why two triangles are congruent with geometric reasons and reference to ASA, SAS, SSS, or RHS. General guidance Students need to prove the equal facts and identify them in the two triangles using geometric reasoning and then to show that the facts fit one of the four criteria. www.bbc.co.uk/schools/gcsebitesize/math s/shapes/congruencysimilarityrev4.shtml www.mathwarehouse.com/classroom/wor ksheets/congruent_triangles/Triangle_pro of_ASA-SAS.pdf www.bbc.co.uk/schools/gcsebitesize/math s/shapes/congruencysimilarityrev3.shtml Teaching activities: Ask students working in groups to construct a variety of triangles with the following criteria. Some will leave them with choices, or prove impossible. Do not tell them they are going to check if they are identical until the end. 1. Sides of 4cm, 5cm, 7cm constructed with any one of those as the base. 2. A base of 5cm with a line at 75° at one end and a line of 6cm at the other end. 3. A base of 6cm with a side drawn at 75° to this that is 5cm long. 4. A base of 8cm, another line of 7cm and the angle opposite to the base of 55°. 5. Draw a parallelogram with sides 5cm and 7cm and cut in half to form v1 2Y01 Cambridge IGCSE Mathematics (US) 0444 3 Syllabus ref Learning objectives Suggested teaching activities Learning resources two triangles. 6. Draw a right angle and sides forming the right angle of 5cm and 9cm. 7. Draw a base of 6cm, a right angle at one end and the hypotenuse at the other end of 9cm. 8. A triangle with angles 40°, 65°, 75°, base of any length. Finally students cut out the triangles and decide when they are identical (even if flipped over) and when they are not, and if any are similar. Are there any other combinations they could invent? Discuss results and the difficulty of constructing some with or without extra decisions. v1 2Y01 Cambridge IGCSE Mathematics (US) 0444 4