Video narration
Still mixing up trigonometry formulas? Start with one right triangle and one acute angle. Its sides are the perpendicular, base, and hypotenuse. From that triangle: sin θ is perpendicular over hypotenuse, cos θ is base over hypotenuse, and tan θ is perpendicular over base. Now the pattern grows. Cosec θ, sec θ, and cot θ are their reciprocals: one over sin θ, one over cos θ, and one over tan θ. Here is the turn: these are not isolated facts. They connect through the identities: sin2θ plus cos2θ equals one; one plus tan2θ equals sec2θ; and one plus cot2θ equals cosec2θ. In revision, redraw the right triangle, mark the angle, recall sin, cos, and tan, flip them for the reciprocals, then use the identity family. Rebuild the map, instead of memorizing a maze.