1. \( sin(\theta) \ = \ \dfrac{বিপরীত \ বাহু}{অতিভুজ} = \ \dfrac{লম্ব}{অতিভুজ} \)
    2. \( cos( \theta ) \ = \ \dfrac{সন্নিহিত \ বাহু}{অতিভুজ} \ = \ \dfrac{ভূমি}{অতিভুজ} \)
    3. \( tan(\theta) \ = \ \dfrac{বিপরীত \ বাহু}{সন্নিহিত \ বাহু} = \ \dfrac{লম্ব}{ভূমি} \)
    1. \( sin \ \theta \ = \ \dfrac{1}{cosec \ \theta}\)
    2. \( cos \ \theta \ = \ \dfrac{1}{sec \ \theta} \)
    3. \( tan \ \theta \ = \ \dfrac{1}{cot \ \theta} \)
    1. \( tan \ \theta \ = \ \dfrac{sin \ \theta}{cos \ \theta} \)
    2. \( cot \ \theta \ = \ \dfrac{cos \ \theta}{sin \ \theta} \)
  1. \( sin^2 \ \theta \ + \ cos^2 \ \theta \ = \ 1 \)
  2. \( sec^2 \ \theta \ - \ tan^2 \ \theta \ = \ 1 \)

    \( \boxed{ tan^2 \ \theta \ = \ sec^2 \ \theta \ - \ 1 } \)
  3. \( cosec^2 \ \theta \ - \ cot^2 \ \theta \ = \ 1 \)

    \( \boxed{ \ cot^2 \theta \ = \ cosec^2 \theta \ - \ 1 } \)