WORK PROGRAM Chapter 10 Right-angled trigonometry Strands: Measurement, Space and geometry, Number, Patterns and algebra Substrands and outcomes: Perimeter and area MS4.1 Uses formulae and Pythagoras’ theorem in calculating perimeter and area of circles and figures composed of rectangles and triangles Trigonometry MS5.1.2 Applies trigonometry to solve problems (diagram given) including those involving angles of elevation and depression Two-dimensional space SGS3.2b Measures, constructs and classifies angles Properties of geometrical figures SGS4.3 Classifies, constructs, and determines the properties of triangles and quadrilaterals Fractions, decimals and percentages NS4.3 Operates with fractions, decimals, percentages, ratios and rates Algebraic techniques PAS4.4 Uses algebraic techniques to solve linear equations and simple inequalities Section Are you ready? (page 296) GC tips, Investigations, History of mathematics, Maths Quest challenge, 10 Quick Questions, Code puzzles, Career profiles SkillSHEETs, WorkSHEETs, Interactive games, Test yourself, Topic tests (CD-ROM) SkillSHEETs (page 296) 10.1: Measuring angles with a protractor 10.3: Rounding to a given number of decimal places 10.4: Solving equations of x the type a = to find x b 10.5: Solving equations of b the type a = to find x x 10.8: Using Pythagoras’ theorem 10.9: Identifying and using Technology applications (CD-ROM) Learning outcomes SGS3.2b using a protractor to measure angles NS4.3 rounding decimals to a given number of decimal places PAS4.4 solving equations using algebraic methods MS4.1 using Pythagoras’ theorem to find the length of sides in rightangled triangles 1 properties of a triangle What is trigonometry? (page 297) Naming the sides of a right-angled triangle (page 297) WE 1, 2, 3a-c Ex 10A Naming the sides of a right-angled triangle (page 302) Investigation: The cosine and tangent ratios (page 300) SkillSHEET 10.1: Measuring angles with a protractor (page 303) Game time 001 (page 305) Cabri geometry: Investigating the sine ratio (page 298) Cabri geometry: Investigating the cosine ratio (page 301) Cabri geometry: Investigating the tangent ratio (page 301) Cabri geometry: Sine, cosine, tangent (page 303) SGS4.3 recognising and classifying types of triangles on the basis of their properties MS5.1.2 identifying the hypotenuse, adjacent and opposite sides with respect to a given angle in a right-angled triangle in any orientation recognising that the ratio of matching sides in similar right-angled triangles is constant for equal angles labelling the side lengths of a rightangled triangle in relation to a given angle e.g. the side c is opposite angle C defining the sine, cosine and tangent ratios for angles in right-angled triangles labelling sides of rightangled triangles in different orientations in relation to a given angle (Applying strategies, Communicating) 2 Trigonometric ratios (page 306) WE 4, 5a-b Ex 10B Trigonometric ratios (page 308) Maths Quest challenge (page 305) Finding trigonometric ratios using a calculator (page 311) WE 6a-c Ex 10C Finding trigonometric ratios using a calculator (page 312) Finding side lengths (page 312) WE 7, 8 Ex 10D Finding side lengths (page 314) GC tip Casio: Finding sin, cos or tan of an angle (page 311) Maths Quest challenge Q1 (page 316) 10 Quick Questions 1 (page 317) SkillSHEET 10.2: Mathcad: Trigonometric Labelling sides of a ratios (page 308) triangle (page 308) Excel: Introducing the trig SkillSHEET 10.3: ratios (page 309) Rounding to a given number of decimal places (page 309) WorkSHEET 10.1 (page 310) GC tip TI: Finding sin, cos or tan of an angle (page 311) SkillSHEET 10.4: Solving equations of the type x a = to find x (page 314) b SkillSHEET 10.5: Solving equations of the type Excel: Using sine (page 314) Excel: Using cosine (page 314) Excel: Using cosine (DIY) (page 315) explaining why the ratio of matching sides in similar right-angled triangles is constant for equal angles (Communicating, Reasoning) MS5.1.2 defining the sine, cosine and tangent ratios for angles in right-angled triangles using trigonometric notation e.g. sin A labelling sides of rightangled triangles in different orientations in relation to a given angle (Applying strategies, Communicating) MS5.1.2 using a calculator to find approximations of the trigonometric ratios of a given angle measured in degrees MS5.1.2 selecting and using appropriate trigonometric ratios in right-angled triangles to find unknown sides, 3 Excel: Using tangent (page 315) Excel: Using tangent (DIY) (page 315) Excel: Universal trigonometric calculator (page 315) Mathcad: Finding side lengths (page 315) SkillSHEET 10.7: Mathcad: Finding angles Rounding angles to the (page 320) nearest degree (page 320) Excel: Finding angles (page 320) b to find x (page 315) x SkillSHEET 10.6: Rearranging formulas (page 315) Game time 002 (page 316) WorkSHEET 10.2 (page 316) a= Finding the size of an angle (page 317) WE 9a-c Ex 10E Finding the size of an angle (page 320) 10 Quick Questions 2 (page 321) Code puzzle (page 322) Applications (page 323) WE 10a-c, 11 Ex 10F Applications (page 326) Investigation: Using an inclinometer to measure inaccessible heights (page 328) History of mathematics: George Everest (page 329) SkillSHEET 10.8: Using Pythagoras’ theorem (page 326) SkillSHEET 10.9: Identifying and using properties of a triangle (page 326) WorkSHEET 10.3 (page 327) Excel: Universal trigonometric calculator (page 326) including the hypotenuse solving problems in practical situations involving right-angled triangles (Applying strategies) MS5.1.2 using a calculator to find an angle correct to the nearest degree, given one of the trigonometric ratios of the angle selecting and using appropriate trigonometric ratios in right-angled triangles to find unknown angles correct to the nearest degree MS5.1.2 selecting and using appropriate trigonometric ratios in right-angled triangles to find unknown sides, including the hypotenuse selecting and using appropriate trigonometric ratios in right-angled triangles 4 Summary (page 330) Chapter review (page 331) to find unknown angles correct to the nearest degree identifying angles of elevation and depression solving problems involving angles of elevation and depression when given a diagram interpreting diagrams in questions involving angles of elevation and depression (Communicating) solving problems in practical situations involving right-angled triangles (Applying strategies) ‘Test yourself’ multiple choice questions Topic tests (2) 5