Average

sum/total number

Area of a circle

πr²

Circumference of a circle

2πr

Arc

circumference(central angle/360)

Sector

area(central angle/360)

Compound interest

A = P (1 + r/n)^ (nt) A = accumulated amount P = principle r = interest rate expressed as decimal n = compounding per period t = number of periods

Exponential growth

y = C(1+r)^t y = final amount C = initial amount r = rate of change t = time

Exponential decay

y = C(1-r)^t y = final amount C = initial amount r = rate of change t = time

Cone volume

(1/3)πr²h

Cylinder volume

πr²h

Cylinder surface area

2πrh+2πr²

Regular prism volume

lwh

Rectangular prism surface area

2lw+2lh+2wh

Rectangular pyramid volume

(1/3)lwh

Sphere volume

(4/3)πr³

equation of a circle

(x-h)² + (y-k)² = r² h = x coordinate of the centre point k = y coordinate of the centre point

parabola standard form

ax² + bx + c

Quadratic formula

x = [-b ± √(b² - 4ac)}/2a

Rhombus area

Bh

Rhombus Perimeter

2b + 2h

Trapezoid area

A = (b1+b2)½h

Polygon interior angles

(n-2)180

Ratio formula

one part/another part

Direct proportional relationship

one part/whole part = one part / whole part

Probability

desired outcomes/total outcomes

Area of a triangle

½bh

Pythagorean Theorem

a²+b²=c²

slope

m = rise/run m = ∆y/∆x m = (y₂-y₁)/(x₂-x₁)

slope intercept form

y=mx+b

% change

change/original