Unlike the SAT, the ACT Math Test does not provide students with a formula chart to aid in solving problems—so unless you’ve got these memorized, you might find yourself up the creek without a paddle on the ACT. Print this list and learn it, students. Learn it well!

## ACT Math Formula Chart

**Circles**

A =

C =

**Rectangles, Parallelograms, and Squares**

A = base x height

**Triangles**

A = bh/2

**Trapezoids**

A =

(Add the bases, divide by two, multiply by the height)

**Rectangular Prisms**

V = lwh

**Cylinders**

V =

**Spheres**

V =

**Cones**

**Pyramids**

V = 1/3 Bh

where B is the area of the base and h is the height

**Pythagorean Theorem**

(where c is the hypotenuse and a and b are legs of a right triangle)

**Special Right Triangles**

**30° − 60° − 90° Right Triangle**

Short leg (opposite the 30° angle) = x

Long leg (opposite the 60° angle) = x√3

Hypotenuse = 2x

**45° − 45° − 90° Right Triangle**

Each leg = x

Hypotenuse = x√2

**Average (Arithmetic Mean)**

Sum of things / number of things

**Median**

Middle number

**Mode**

Most frequent number

**Trigonometry**

SOHCAHTOA

sin x = opposite / hypotenuse

cos x = adjacent / hypotenuse

tan x = opposite / adjacent

In Quadrant I (top right), sin, cos, and tan are positive.

In Quadrant II (top left), sin is positive, and cos and tan are negative.

In Quadrant III (bottom left), sin and cos are negative, and tan is positive.

In Quadrant IV (bottom right), sin is negative, cos is positive, and tan is negative.

**Probability**

Number of desired outcomes / number of total outcomes

**Factorials**

5! = 5 x 4 x 3 x 2 x 1

**Equation of a Circle**

**Logarithms**

**Change of Base Rule**

**Exponential Growth Formula**

where A is the new amount, P is the principal amount, r is the rate of growth, n is the number of months, and t is time in years.

**Quadratic Formula**

Negative b plus or minus the square root of b squared minus 4ac over 2a.