irrational numbers natural numbers radical sign rational numbers recurring decimal scientific notation square root common factor difference of two squares distributive law highest common factor angle of depression angle of elevation cosine ratio Pythagoras’ theorem Pythagorean triad right-angled triangle sine ratio trigonometric inverses trigonometric ratios composite shape cross-section plane figure total surface area integers numerator recurs surd binomial coeffcient constant evaluate expand expression factorise FOIL pronumeral simplify substitution terms trinomial variable adjacent hypotenuse inverse opposite 'tangent ratio" 3-dimensional arc area capacity circle circumference cube cuboid cylinder hectare length net perimeter prism quadrant radii sector semicircle volume