SAT Right Triangle Trigonometry

Right-triangle trigonometry tests sine, cosine and tangent as ratios of sides, plus the Pythagorean theorem and special triangles. Nearly every error is picking the wrong ratio or swapping which side is adjacent and which is the hypotenuse.

Practise this skill freeHow the SAT is structured
MathGeometry and Trigonometry68 questions
The trap on this skill

Using the sine ratio or reversing adjacent and hypotenuse.

How this skill behaves

What 68 questions on it look like

90% of these questions can appear in the harder second module. On a section-adaptive test that matters: this is a skill that keeps mattering after a strong first module, not one you leave behind.

Not one question in this skill is rated hard. What makes it cost marks is speed and carelessness, not difficulty.

medium90%
easy10%

Difficulty mix across the 68 questions in this skill.

From the bank

Three real right triangle trigonometry questions

Each one explains the credited answer and why every other option fails.

Geometry and Trigonometry · medium

A support in the garden weekday bracket screening order slip is modeled by a right triangle. For angle A, the opposite side is 3 and the hypotenuse is 5. What is cos A?

  1. A3/5
  2. B4/5correct
  3. C3/4
  4. D5/4
Why B is correct — and why the others are not

The adjacent side is 4 by the 3-4-5 right triangle. Therefore cos A = adjacent/hypotenuse = 4/5. This matches the evidence or condition involving Right triangle trigonometry. A final check is checking that both equations or conditions are satisfied.

A. This value results from using the sine ratio or reversing adjacent and hypotenuse

C. This value results from using the sine ratio or reversing adjacent and hypotenuse

D. This value results from using the sine ratio or reversing adjacent and hypotenuse

Geometry and Trigonometry · easy

A support in the lakeside quiet pump timing ledger is modeled by a right triangle. For angle A, the opposite side is 3 and the hypotenuse is 5. What is cos A?

  1. A3/5
  2. B4/5correct
  3. C3/4
  4. D5/4
Why B is correct — and why the others are not

The adjacent side is 4 by the 3-4-5 right triangle. Therefore cos A = adjacent/hypotenuse = 4/5. This matches the evidence or condition involving Right triangle trigonometry. A final check is confirming that the selected expression has the same domain.

A. This value results from using the sine ratio or reversing adjacent and hypotenuse

C. This value results from using the sine ratio or reversing adjacent and hypotenuse

D. This value results from using the sine ratio or reversing adjacent and hypotenuse

Geometry and Trigonometry · medium

A support in the ticketbooth weekend crate checkout time card is modeled by a right triangle. For angle A, the opposite side is 5 and the hypotenuse is 13. What is cos A?

  1. A5/13
  2. B5/12
  3. C12/13correct
  4. D13/12
Why C is correct — and why the others are not

The adjacent side is 12 by the 5-12-13 right triangle. Therefore cos A = adjacent/hypotenuse = 12/13. The final step answers the prompt as it applies to Right triangle trigonometry. A final check is following the order of operations in the displayed expression.

A. This value results from using the sine ratio or reversing adjacent and hypotenuse

B. This value results from using the sine ratio or reversing adjacent and hypotenuse

D. This value results from using the sine ratio or reversing adjacent and hypotenuse

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FAQ

Right Triangle Trigonometry questions

How do I remember the trig ratios?

SOH-CAH-TOA: sine is opposite over hypotenuse, cosine adjacent over hypotenuse, tangent opposite over adjacent — all relative to the angle you are using.

Which triangles should I know?

30-60-90 and 45-45-90, and the 3-4-5 and 5-12-13 Pythagorean triples. They turn several questions into recall.
Last reviewed 2026-08-28. Format and scoring facts sourced to College Board. Question counts describe the PrepScore bank, not the exam.
Same domain
Lines, Angles, and Triangles67 questionsCircles67 questionsCoordinate Geometry60 questionsArea and Volume42 questions

Practise right triangle trigonometry until the trap stops working.

Real Digital SAT questions, the reasoning on every option, and a mistake bank that only clears when you get it right.

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