SAT Math Domain
SAT Geometry & Trigonometry
Tests geometric properties of lines, angles, triangles, circles, 3D solids, right-triangle trigonometry, and radian-degree transformations.
What the SAT Tests in Geometry & Trigonometry
Area and volume of 2D shapes and 3D solids (spheres, cylinders, prisms, cones)
Circle theorems, arc lengths, sector areas, and standard circle equations (x - h)^2 + (y - k)^2 = r^2
Right triangle trigonometry (SOH CAH TOA) and complementary angle identity sin(x) = cos(90° - x)
Similar triangles and proportional side lengths
Formulas & Shortcuts
High-Yield Formulas & Desmos Rules
Circle Equation(x - h)^2 + (y - k)^2 = r^2
(h, k) is the center and r is radius.
Complementary Trig Rule\sin(x^\circ) = \cos(90^\circ - x^\circ)
The sine of an acute angle equals the cosine of its complement.
Sector AreaA = \frac{\theta}{360^\circ} \times \pi r^2 \quad \text{or} \quad \frac{1}{2}r^2\theta \text{ (radians)}
Proportional fraction of full circle area.
Common Student Traps
- •Forgetting that the right side of the circle equation is r^2, not r.
- •Mixing up degree and radian modes on trigonometry questions.
Proven Study Strategies
- •The SAT provides a formula reference sheet on screen during the test; familiarize yourself with all formulas on it.
- •Remember that completing the square is often required to turn an expanded circle equation into standard form.
Example Questions & Solutions
Step-by-step walkthroughsExample Question #1easy Difficulty
In right triangle ABC, angle C is 90 degrees. If sin(A) = 3/5, what is the value of cos(B)?
A.3/5
B.4/5
C.3/4
D.5/3
Solution (Option A):
In a right triangle where C = 90°, angles A and B are complementary (A + B = 90°). By trigonometric identity, cos(B) = sin(90° - B) = sin(A) = 3/5.
Frequently Asked Questions
How many Geometry questions are on the SAT?
Geometry and Trigonometry make up about 5 to 7 questions (approx 15% of the Math section).