This eBook introduces the related subjects of Pythagoras’ theorem and trigonometry, as Pythagoras’ theorem relates to all right-angles triangles, trigonometry as it relates to angles and ratios of sine, cosine and tangent in right-angled triangles as well as angles of elevation and depression.This eBook is part of our range of Grades 9 & 10 math eBooks that are aligned with the North American curriculum.Our Grades 9 & 10 math eBooks comprise three principle sections. These are, notably:•Number and Algebra•Geometry and Measures•StatisticsIn addition, there exists a Publications Guide.Our maths eBook are produced such as that as well as a Publications Guide, and three principle publications corresponding to the principle sections (Number and Algebra, Geometry and Measures and Statistics) there are individual modules produced within each principle section which are published as eBooks.Pythagoras’ Theorem and Trigonometry is a module within the Geometry and Measures principle section of our Key Stage 4 (KS4) publications.