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 (b 1 +b 2 )·h

Slope Formula m = y 2 -y 1 x 2 -x 1

Slope-Intercept Equation of a Line y = mx + b

Distance Formula D = √w

Midpoint Formula M= x 1 +x 2 y 1 +y 2 2, 2

Pythagorean Theorem a 2 + b 2 = c 2

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