ACT Math Test Essential Knowledge

Area of a Circle

Circumference of a Circle

Area of a Triangle

½ b·h

Area of a Rectangle

b·h

Perimeter

= Sum of all sides

Example: Perimeter of Rectangle = 2b + 2h

Area of a Trapezoid

½ (b1+b2)·h

Slope Formula

m = y2-y1

x2-x1

Slope-Intercept Equation of a Line

y = mx + b

Distance Formula

D = √w

Midpoint Formula

M= x1+x2 y1+y2

2 , 2

Pythagorean Theorem

a2 + b2 = c2

Trig Rations

sin = opposite

hypotenuse

cos = adjacent

hypotenuse

tan = opposite

adjacent

******Remember: SOH-CAH-TOA

Special Right Triangles

Mean

= sum of terms

number of terms

Median

Middle term in an ordered data set

(If there is an even number of terms, take the average of the two middle terms.)

Mode

Most frequently occurring term

in a data set