SAT Trigonometry Rules & Identities (SOH-CAH-TOA Cheat Sheet)
Master the trigonometry formulas tested on the Digital SAT.
The core trigonometry rules for the SAT are: 1. SOH-CAH-TOA: sin(θ) = Opp/Hyp, cos(θ) = Adj/Hyp, tan(θ) = Opp/Adj. 2. Complementary Angle Identity: sin(x°) = cos(90° - x°). 3. Radians to Degrees: Multiply radians by 180/π. 4. Pythagorean Identity: sin²(θ) + cos²(θ) = 1.
Trigonometry accounts for roughly 2 to 4 questions per test. The complementary angle identity sin(A) = cos(B) where A + B = 90° appears on almost every exam.
Reference Data Table
| Trig Concept / Formula | Equation | Exam Application |
|---|---|---|
| SOH-CAH-TOA | sin = O/H, cos = A/H, tan = O/A | Right triangle side ratio calculations |
| Complementary Angle Identity | sin(x°) = cos(90° - x°) | If sin(3x) = cos(2x), then 3x + 2x = 90 |
| Radians to Degrees Conversion | Degrees = Radians × (180 / π) | Converting angle units in circle sectors |
| Pythagorean Identity | sin²(θ) + cos²(θ) = 1 | Simplifying algebraic trigonometric equations |
| Tangent Identity | tan(θ) = sin(θ) / cos(θ) | Converting between ratios without right triangles |
Key Takeaways & Pro Tips
Frequently asked questions
Is the unit circle provided on the SAT reference sheet?
No. The reference sheet does NOT include any trigonometry identities or unit circle values.
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