As Razões Trigonométricas: Seno, Cosseno e Tangente

Section role: supports Section 2 ('As Razões Trigonométricas: Seno, Cosseno e Tangente') while the teacher introduces the formal definitions on the board and guides the class through the mnemônico SOH CAH TOA. Slides: (1) Title — 'As Razões Trigonométricas: Seno, Cosseno e Tangente'; (2) O Triângulo Retângulo — bullets: review of 90° angle, hypotenusa, and the two legs from Section 1; (3) O Conceito de Catetos — definitions and distinction between Cateto Oposto (CO) and Cateto Adjacente (CA) relative to an angle alfa; (4) Seno — definition Sen = CO/H with a visual triangle diagram; (5) Cosseno — definition Cos = CA/H highlighting the adjacent leg and hypotenusa; (6) Tangente — definition Tan = CO/CA relating the two legs; (7) O Mnemônico SOH CAH TOA — a large visual guide breaking down SOH, CAH, and TOA for easy memorization; (8) Exemplo Prático Guiado — a triangle with an angle of 30º and hypotenusa of 10 units, calculating the opposite leg step by step; (9) Cuidado com o Ângulo de Referência — discussion on the common error of swapping the opposite and adjacent legs when shifting the reference angle; (10) Ângulos Notáveis — introduction to 30º, 45º, and 60º values and the importance of proportions. Closing slide: 'Se mudarmos o ângulo de referência para o outro vértice agudo, quem era cateto oposto continua sendo o mesmo?' — hands control back to the teacher for discussion and sets up the problem-solving tasks in Section 3.

Lara da Teachy