31 Critical ACT Math Formulas| Questions with 100% correct Answers | Verified and updated

slope - (y₂-y₁)/(x₂-x₁) slope-intercept form - y=mx+b midpoint formula - ((x₁+x₂)/2, (y₁+y₂)/2) distance formula - (√(x₂-x₁)²+(y₂-y₁)²) logarithms - log(b)x=y - b^y=x mean - (sum of terms/amount of terms) speed - (total distance/total time) probability of an outcome - (number of desired outcomes/total number of possible outcomes) combinations - x*y*z x percent of a given number n - ((n)(x/100)) how much n percent is of another number - ((100n)/m) number in is x percent of - ((100n)/x) area of rectangle - l×wperimeter of a rectangle - (2l+2w) volume of a rectangular solid - V=l*w*h area of a parallelogram - A=l*h area of a triangle - ½b*h pythagorean theorem - a²+b²=c² isosceles triangle - 2 sides of equal length, 2 equal angles 45-45-90 triangle - x-x-x√2 30-60-90 triangle - x-x√3-x√2 area of a trapezoid - (parallel side a + parallel side b)/2 area of a circle - A=πr² area of an arc - (A=πr²)(degree measure center of an arc/360) circumference of an arc - (2πr)(degree measure center of arc/360) equation of a circle - ((x-h)²+(y-k)²=r²) volume of a cylinder - V=πr²h