How to Use the Provided Math Formulas and Reference Sheet on the Digital SAT

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By Glyn Caddell, BSME · Author of Digital SAT Math Secrets · Tutoring since 2008 — Updated August 3, 2026

The Digital SAT provides a math reference to students during the math modules. It can be accessed during the test by pressing the icon on the top right with an $x^2$ and the word “Reference” underneath it. The reference includes formulas for 2-D shapes, such as circles, rectangles, and triangles. It includes volume formulas for 3-D shapes.

Table of Contents

The Provided Formulas
Tips
Formulas Not Provided but are Needed

The Provided Formulas

The Digital SAT provides some formulas for circles, rectangles, triangles, and 3-D shapes. Mathematical relationships are also provided for special right triangles.

Area and Circumference of a Circle

The formula for area of a circle is provided.

$A=\pi r^2$

The formula for circumference of a circle is also provided.

$C=2\pi r$

where $A$ is the area, $C$ is the circumference, and $r$ is the radius.

Video Explaining the Circle Formulas with an Example

Area of a Rectangle

The formula for area of a rectangle is provided.

$A=lw$

where $A$ is the area, $l$ is the length, and $w$ is the width.

Video Explaining the Area of a Rectangle with an Example

Area of a Triangle

The formula for area of a triangle is provided.

$A=\dfrac{1}{2}bh$

where $A$ is the area, $b$ is the base, and $h$ is the height.

Video Explaining the Area of a Triangle

Pythagorean Theorem

The formula for Pythagorean Theorem is provided.

$c^2=a^2+b^2$

where $c$ is the hypotenuse (the side across from the 90 degree angle), and $a$ and $b$ are the legs (sides other than the hypotenuse).

Video Explaining the Pythagorean Theorem

30-60-90 Triangle

The relationship among the sides of 30-60-90 right triangle are provided.

There is a ratio that exists among the sides.

The hypotenuse is $2x$

The side opposite (across from) the 30 degree angle is $x$

The side opposite the 60 degree angle is $x\sqrt{3}$

If you know the lengths of any of the sides, you can solve for $x$ and then calculate the lengths of the other sides.

Video Explaining the Side Relationships in a 30-60-90 Triangle with an Example

45-45-90 Triangle

The relationship among the sides of 45-45-90 right triangle are provided.

There is a ratio that exists among the sides.

The hypotenuse is $s\sqrt{2}$

Since two angles are both 45 degrees, this is an isosceles triangle, making the two sides opposite the 45 degree angles congruent. They are both $s$

If you know the lengths of any of the sides, you can solve for $x$ and then calculate the lengths of the other sides.

Video Explaining the Side Relationships in a 45-45-90 Triangle with an Example

Volume of a Rectangular Prism

The formula for volume of a rectangular prism is provided.

$V=lwh$

where $V$ is the volume, $l$ is the length, $w$ is the width, and $h$ is the height.

Video Explaining the Volume of a Rectangular Prism with an Example

Volume of a Cylinder

The formula for volume of a cylinder is provided.

$V=\pi r^2h$

where $V$ is the volume, $r$ is the radius of the circle, and $h$ is the height.

Video Explaining the Volume of a Cylinder with an Example

Volume of a Sphere

The formula for volume of a sphere is provided.

$V=\dfrac{4}{3}\pi r^3$

where $V$ is the volume and $r$ is the radius.

Video Explaining the Volume of a Sphere with an Example

Volume of a Cone

The formula for volume of a cone is provided.

$V=\dfrac{1}{3}\pi r^2h$

where $V$ is the volume, $r$ is the radius, and $h$ is the height.

Video Explaining the Volume of a Cone with an Example

Volume of a Pyramid

The formula for volume of a pyramid is provided.

$V=\dfrac{1}{3} lwh$

where $V$ is the volume, $l$ is the length, $w$ is the width, and $h$ is the height.

Video Explaining the Volume of a Pyramid with an Example

Radians & Degrees Relationship

The math reference states the following two facts:

The number of degrees of arc in a circle is 360.

The number of radians of arc in a circle is $2\pi$

By stating these two facts, it also tells us how degrees and radians are related:

$360^o=2\pi rad$

Review our circles to see how these relationships come in handy.

Video Explaining the Relationship Between Radians and Degrees, Including How to Convert From One to the Other

Sum of the Angles in a Triangle

The sum of the measures of the angles in a triangle is 180.

Video Explaining the Sum of the Angles in a Triangle with an Example

Tips to Use the Math Sheet Effectively

Familiarize yourself with the formulas before the test
Practice answering SAT questions using the formulas
Memorize the following formulas and relationships because it will save you time on the test:
1. Area of Circle
2. Circumference of a Circle
3. Area of a Rectangle
4. Area of a Triangle
5. Pythagorean Theorem
6. 30-60-90 Triangle
7. 45-45-90 Triangle
8. Volume of a Prism
9. Radians & Degrees Relationships
10. Sum of the Angles of a Triangle

Formulas Not Provided but are Needed

Slope formula:
- To find the slope from one, $(x_1, y_1)$ , point to another, $(x_2, y_2)$
Slope-intercept form of a line:
- where $m$ is the slope and $b$ is the $y$ -intercept
Standard form of a quadratic function: $f(x)=ax^2+bx+c$
Quadratic formula:
- $a$ , $b$ , and $c$ are the coefficients from the standard form, $f(x)=ax^2+bx+c$
Vertex-form of a quadratic function:
- where (h, k) is the vertex
Factored form of a quadratic function:
- where $p$ and $q$ are the zeros (roots)
Standard form of a circle:
- where (h, k) is the center and the radius is <em>r</em>
Exponential growth/decay:
- Where $A$ is the amount, $A_0$ is the starting amount, $r$ is the percent change, and $t$ is the number of time periods
Average: $Average=\dfrac{Sum}{NumberOfTerms}$ and $Sum=(Average)\times(Number Of Terms)$
The sum of the interior angles of a convex polygon:
- where $n$ is the number of sides
The sum of the exterior angles of any convex polygon is always $360^o$
SOH-CAH-TOA
- $sinA=\dfrac{opposite}{hypotenuse}$
- $cosA=\dfrac{adjacent}{hypotenuse}$
- $tanA=\dfrac{opposite}{adjacent}$
- Valid in right triangles only. Angle A represents one of the acute angles in the right triangle

All Math Topics

All of our math topics are available here: https://caddellprep.com/sat/prep/how-to/mathematics/ for you to review and improve on your SAT. There are lessons, practice problems, and video explanations for you. If you need more help, try our on-demand SAT course with video lessons, practice tests, and sets of questions for each topic: https://caddellprep.com/sat/prep/on-demand/

Glyn Caddell

Glyn Caddell holds a BS in Mechanical Engineering from NJIT and has been tutoring New York City students since 2008. He founded Caddell Prep in 2012 and is the author of Digital SAT Math Secrets: Lessons & Tricks to Quickly Improve to a Perfect 800 on the Math Test, which contains over 900 practice problems and is used in Caddell Prep’s SAT math classes. He is founding president of the Staten Island Technical High School alumni association and teaches every lesson on this site personally.