Trigonometry — O/L Mathematics

Trigonometry is the study of relationships between the sides and angles of triangles. In Grade 11, we focus on right-angled triangles and extend these ideas to the unit circle, enabling us to work with angles of any size. The fundamental concept is that for a given acute angle in a right-angled triangle, the ratios of pairs of sides are constant, regardless of the triangle's size. The Three Primary Trigonometric Ratios

Consider a right-angled triangle with an acute angle θ (theta). The sides are named relative to θ: Hypotenuse (h): The side opposite the right angle; always the longest side. Opposite side (o): The side directly across from angle θ. Adjacent side (a): The side next to angle θ (not the hypotenuse).

The three primary ratios are defined as: Sine (sin θ): sin θ = opposite / hypotenuse = o / h Cosine (cos θ): cos θ = adjacent / hypotenuse = a / h Tangent (tan θ): tan θ = opposite / adjacent = o / a