The digital SAT provides a built-in reference of basic geometric formulas, but the formulas that actually move the score are unlisted. This cheat sheet covers both. For the SAT Math curriculum see SAT Math; for the test format see the digital SAT complete guide.
On the printed reference (memorise anyway)
Area of circle πr², area of triangle ½bh, Pythagorean theorem a² + b² = c², 30-60-90 triangle 1 : √3 : 2, 45-45-90 triangle 1 : 1 : √2, volume of rectangular solid lwh, volume of cylinder πr²h.
Not on the reference (highest leverage)
Slope: (y₂ − y₁) / (x₂ − x₁). Midpoint: ((x₁+x₂)/2, (y₁+y₂)/2). Distance: √((x₂−x₁)² + (y₂−y₁)²). Quadratic vertex: x = −b/2a. Exponential growth: y = a(1+r)^t.
Statistics on the digital SAT
Mean changes when adding a value; median often does not. Standard deviation increases with spread, not with shift.
Frequently asked questions
Does the digital SAT give a calculator?
Yes — Desmos is built into Bluebook. Use it but do not over-rely; many questions are faster solved by hand.
What math topics are most heavily tested on the digital SAT?
Linear equations and functions, quadratic functions, ratios/proportions/percentages, and geometry — in roughly that order.
Are trigonometry questions on the digital SAT?
Yes — basic SOH-CAH-TOA, complementary angles, and unit-circle radians.