1. ACT Math Test Essential Knowledge

2. Area of a Circle

3. Circumference of a Circle

4. Area of a Triangle ½ b·h

5. Area of a Rectangle b·h

6. Perimeter = Sum of all sides Example: Perimeter of Rectangle = 2b + 2h

7. Area of a Trapezoid ½ (b 1 +b 2 )·h

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

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

10. Distance Formula D = √w

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

12. Pythagorean Theorem a 2 + b 2 = c 2

13. Trig Rations sin  = opposite hypotenuse cos  = adjacent hypotenuse tan  = opposite adjacent ******Remember: SOH-CAH-TOA

14. Special Right Triangles

15. Mean = sum of terms number of terms

16. Median Middle term in an ordered data set (If there is an even number of terms, take the average of the two middle terms.)

17. Mode Most frequently occurring term in a data set