ত্রিকোণমিতির সূত্রাবলী

sinθ = लম্ব/অতিভূজ

cosθ = ভূমি/অতিভূজ

taneθ = लম্ব/ভূমি

cotθ = ভূমি/লম্ব

secθ = অতিভূজ/ভূমি

cosecθ = অতিভূজ/লম্ব

sinθ = 1/cosecθ, cosecθ=1/sinθ

cosθ = 1/secθ, secθ=1/cosθ

tanθ = 1/cotθ, cotθ=1/tanθ

sin²θ + cos²θ = 1

sin²θ = 1 – cos²θ

cos²θ = 1- sin²θ

sec²θ – tan²θ = 1

tan²θ = sec²θ – 1

cosec²θ – cot²θ = 1

cosec²θ = cot²θ + 1

cot²θ = cosec²θ – 1