Side opposite of angle / hypotenuse.
Key Idea: Sine (sin)
In a right triangle, the sine of an angle is the ratio of the side opposite the angle to the hypotenuse.
General Rule:
sin(θ)=Opposite Side / Hypotenuse
Only applies to right triangles.
Helps find missing side lengths or angles when combined with other trig ratios.
Why this matters for the SAT:
Sine is essential in trigonometry questions on the SAT.
It allows you to solve for unknown sides or angles in right triangles quickly using ratios.
Side adjacent to angle / hypotenuse.
In a right triangle, cosine of an angle measures the ratio between the adjacent side and the hypotenuse.
cos(θ) = adjacent side / hypotenuse
Cosine is frequently used to find missing sides or angles in right triangles and in trigonometric equations. Recognizing which side is adjacent versus opposite is crucial for setting up the correct ratio.
Side opposite of angle / side adjacent to angle.
Key Idea: Tangent (tan)
In a right triangle, the tangent of an angle is the ratio of the side opposite the angle to the side adjacent to the angle.
General Rule:
tan(θ) = Opposite Side / Adjacent Side
Only applies to right triangles.
Useful for finding missing sides or angles when combined with other trigonometric ratios.
Why this matters for the SAT:
Tangent is a core trigonometric ratio on the SAT.
It allows you to solve for unknown sides or angles in right triangle problems efficiently.
